## Dr. Székelyhidi László tudományos előadásai

- Spectral synthesis on locally compact Abelian groups, Budapest, Hungary: Analysis Seminar, Rényi Institute, September 28, 2023.
- New Results on Spectral Synthesis, Będlewo, Poland: 20th International Conference on Functional Equations and Inequalities, September 17-23, 2023.
- Remarks on non-discrete spectral synthesis. Cluj Napoca, Romania, Theodor Angheluta Seminar, July 11–13, 2023.
- New Results in Spectral Synthesis on Varieties Hajdúszoboszló, Hungary, 59th International Symposium on Functional Equations, June 18– 25, 2023.
- On a Generalization of The Heisenberg Group. The 22nd Debrecen–Katowice Winter Seminar, Hajdúszoboszló, Hungary, February 1-4, 2023.
- Kalahari Math – Secondary school mathematics competitions in Botswana. (in Hungarian) Pécs, Hungary, Scientific Meeting, Pécs Academic Committee, October 18, 2022.
- So, is it knowable or not? (in Hungarian) Pécs, Hungary, Scientific Meeting, Pécs Academic Committee, October 19, 2022.
- János Aczél In His Own Work. Innsbruck, Austria, 58nd International Symposium on Functional Equations, June 19–26, 2022.
- Spectral Analysis and Spectral Synthesis on Lie Groups. (in Hungarian) Debrecen, Hungary, Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, June 11-13, 2022.
- A Sneak Peak In The Ivory Tower – What does a mathematician count? (in Hungarian) Széchenyi University, Győr, Hungary, ”Műteremház”, February 23, 2022.
- A Sneak Peak In The Ivory Tower – What does a mathematician count? (in Hungarian) Hegyeshalom, Hungary, Community Center, February 20, 2022.
- Invariant Subspaces Over The Heisenberg Group. The 21st Debrecen– Katowice Winter Seminar, Brenna, Poland, February 2-5, 2022.
- A Sneak Peak In The Ivory Tower – What does a mathematician count? (in Hungarian) Dunakiliti, Hungary, Community Center, December 9, 2021.
- Moment Functions and Bell Polynomials. (in Hungarian) Debrecen, Hungary: Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, August 27-29, 2021.
- Functional Equations, Moment Functions and Bell Polynomials. Bedlewo, Poland: 19th International Conference on Functional Equations and Inequalities, August 12–18, 2021.
- Generalized Moment Functions on Hypergroups. (in Hungarian), Debrecen, Hungary: Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, June 28-30, 2020.
- Spectral Synthesis on the Affine Group of the Unitary Group, Debrecen, Hungary: HSA 2020 Harmonic and Spectral Analysis, Institute of Mathematics and Informatics, online, June 8-10, 2020.
- Spectral Analysis and Semi-simple Measure Algebras}, Debrecen, Hungary, Seminar talk, Institute of Mathematics, University of Debrecen, November 14, 2019.
- Quantum probability fields, random walks and hypergroups. (in Hungarian), Miskolc, Hungary, Seminar talk, Institute of Mathematics, University of Miskolc, November 12, 2019.
- Functional equations via spectral synthesis, Krakow, Poland, AGH University of Science and Technology, DEA 2019, September 16-20, 2019.
- Addition theorems, functional equations and spectral synthesis, Cluj Napoca, Romania, Theodor Angheluta Seminar, July 3-6, 2019.
- Functional Equations on Infinite Hypergroup Joins, Bedlewo, Poland: 18th International Conference on Functional Equations and Inequalities, June 9-15, 2019.
- Invariant Means and Their Applications (in Hungarian). Miskolc, Hungary, Seminar talk, Institute of Mathematics, University of Miskolc, November 7, 2018.
- Stability of functional equations related to spherical functions. Conference on Ulam’s Type Stability, Timisoara, Romania, October 8-13, 2018.
- Functional Equations for Exponential Polynomials. Debrecen, Hungary, Seminar talk, Institute of Mathematics, University of Debrecen, October 3, 2018.
- Professor Zoltán Daróczy is 80, Laudation talk. Hajdúszoboszló, Hungary, „Numbers, Functions, Equations NFE’18”, August 26 – September 1, 2018.
- Harmonic and Spectral Synthesis. Palapye, Botswana, International Workshop on Mathematical Analysis, BIUST, August 9, 2018.
- Spectral Synthesis and Invariant Differential Operators. Graz-Mariatrost, Austria: 56th International Symposium on Functional Equations, June 17-24, 2018.
- Spherical Spectral Synthesis. Modern Methods and Applications of Operator Theory and Harmonic Analysis VIII, (OTHA), April 22-27, 2018, Rostov on Don, Russia
- Spectral Synthesis and Invariant Differential Operators. Debrecen, Hungary, International Spring Workshop on Mathematical Analysis, University of Debrecen, April 3, 2018.
- Spectral Synthesis on Affine Groups. Pécs, Hungary, 6th Workshop on Fourier Analysis and Related Fields, August 24-31, 2017,
- Exponential Polynomials on Affine Groups. Bedlewo, Poland: 17th International Conference on Functional Equations and Inequalities, July 9-15, 2017.
- Polynomial Functions on Affine Groups. Chengdu, China: 55th International Symposium on Functional Equations, Special Session, June 11-18, 2017.
- New Developments in the Theory of Spectral Analysis and Spectral Synthesis. Chengdu, China: 55th International Symposium on Functional Equations, June 11-18, 2017.
- Spectral analysis and synthesis. Mashad, Iran, Seminar talk at Ferdowsi University, February 22, 2017.
- Spectral synthesis on double coset hypergroups. Isfahan, Iran, IPM Institute for Research in Fundamental Sciences, February 21, 2017.
- Introduction and preliminaries of spectral analysis and synthesis. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
- Spectral synthesis on discrete Abelian groups. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
- Spectral synthesis on non-discrete Abelian groups. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
- Spectral analysis and synthesis on hypergroups. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
- Open problems on spectral analysis and synthesis. Applications. Qom, Iran, International Workshop on Mathematical Analysis, University of Qom, February 19, 2017.
- Functional equations on hypergroups. An introduction. Gaborone, Botswana, Department Seminar, University of Botswana, February 2, 2017.
- Spectral Synthesis on Gelfand Pairs. Debrecen,Hungary, Research Seminar of the Institute of Mathematics, University of Debrecen, January 11, 2017.
- Spherical Spectral Synthesis. Hajdúszoboszló, Hungary, Conference on Inequalities and Applications CIA’16, August 28-September 3, 2016.
- Functional equations on affine groups. Hajdúszoboszló, Hungary: 54th International Symposium on Functional Equations, June 12-19, 2016.
- Remark on spectral synthesis. Hajdúszoboszló, Hungary: 54th International Symposium on Functional Equations, Remark, June 12-19, 2016.
- Hypergroups and Quantum Probability Spaces. Department Seminar, University of Botswana, Gaborone, Botswana, May 12, 2016.
- Mathematics and Adventure – Fermat’s Last Theorem, World Science Day, University of Botswana, Gaborone, Botswana, November 10, 2015.
- Discrete Spectral Synthesis Problems on Varieties, Budapest, Hungary, 5th Workshop on Fourier Analysis and Related Fields, 24-28 August, 2015
- Graph properties of additive and related functions. Department Seminar, University of Botswana, Gaborone, Botswana, August 20, 2015.
- Functional Equations on Discrete Abelian Groups. (in Hungarian) Debrecen, Hungary: Analysis Conference on the occasion of the 80th birthday of Sándor Kántor, Institute of Mathematics, University of Debrecen, July 3-5, 2015.
- On the graph of additive and related functions. Krynica, Poland, 53rd International Symposium on Functional Equations, June 14-21, 2015.
- Functional Equations and Stability Problems on Hypergroups. Bedlewo, Poland: 16th International Conference on Functional Equations and Inequalities, May 17-23, 2015
- On the powers of maximal ideals in the measure algebra, Debrecen, Hungary, Research Seminar, Department of Analysis, Institute of Mathematics, University of Debrecen, May 6, 2015. (via Skype)
- Spectral Analysis and Spectral Synthesis.Course for PhD students, Silesian University, Katowice Poland, November 3-7, 2014.
- Solving functional equations via spectral synthesis. Hajdúszoboszló, Hungary, Conference on Inequalities and Applications CIA’14, Szeptember 7-13, 2014.
- Discrete spectral synthesis on varieties. Seoul, South-Korea, International Congress of Mathematicians ICM2014, August 13-21, 2014.
- On the graph of additive functions. Innsbruck, Austria, 52nd International Symposium on Functional Equations, Remark, June 22-29, 2014.
- Remark on alien-like functional equations. Innsbruck, Austria, 52nd International Symposium on Functional Equations, Special session, June 22-29, 2014.
- A characterization of polynomial functions. Innsbruck, Austria, 52nd International Symposium on Functional Equations, June 22-29, 2014.
- Fréchet’s Functional Equation and Spectral Synthesis. University of Jaén, Seminar at the Department of Mathematics, Jaén, Spain, June 13, 2014.
- Spectral synthesis and difference equations. University of Granada, Seminar at the Department of Mathematics, Granada, Spain, June 12, 2014.
- Stability of functional equations on hypergroups. Conference on Ulam’s Type Stability, Rytro, Poland, June 2-6, 2014.
- Classes of polynomial functions. BIUST (Botswana International Univeristy of Science and Technology), Seminar at the Department of Mathematics, Gaborone, Botswana, March 19, 2014.
- Finite Dimensional Translation Invariant Function Spaces. University of Botswana, Seminar at the Department of Mathematics, Gaborone, Botswana, October 17, 2013.
- Spectral Synthesis on Abelian Groups. 4th Conference on Topology, Algebra, Analysis and Geometry, 11-13 September, 2013, Gaborone, Botswana
- Spectral Analysis and Synthesis on Abelian Groups. 4th Workshop on Fourier Analysis and Related Fields, 26-30 August, 2013, Budapest, Hungary
- On Exponential Polynomials. NFE Numbers, Functions, Equations 2013, Visegrád, Hungary, June 28–30, 2013.
- On Exponential Polynomials. The 13th Debrecen–Katowice Winter Seminar, Zakopane, Poland, January 27–30, 2013.
- Diﬀerence Equations and Spectral Synthesis. (in Hungarian) University of Pannonia, Seminar at the Institute of Mathematics, Veszprém, Hungary, November 13, 2012.
- The Lord of the Rings, the Lady of the Rings and the Spectral Synthesis. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Debrecen, Hungary, November 8, 2012.
- A characterization of exponential polynomials. Katowice, Poland, Seminar at the Mathematical Institute, Silesian University, September 28, 2012.
- What is spectral synthesis? Krynica-Zdrój, Poland: Summer School 2012, Mathematical Institute, Silesian University, September 24–27, 2012.
- Remarks on spectral synthesis. München-Garching, Germany: Harmonic Analysis, Convolution Algebras, Special Functions 2012, September 10– 14, 2012.
- Spectral synthesis and the structure of polynomial functions. Hajdúszoboszló, Hungary: 50th International Symposium on Functional Equations, June 17–24, 2012.
- Spectral Synthesis on Vector Modules. The 12th Debrecen–Katowice Winter Seminar, Hajdúszoboszló, Hungary, January 26–29, 2012.
- Polynomial Functions on Abelian Groups. Bedlewo, Poland: 14th International Conference on Functional Equations and Inequalities, September 11–17, 2011.
- Spectral Synthesis Problems on Locally Compact Groups. Graz-Mariatrost, Austria: 49th International Symposium on Functional Equations, June 14–20, 2011.
- A Moment Problem on Hypergroups I.. The 11th Debrecen–Katowice Winter Seminar, Wisla, Poland, February 1–4, 2011.
- Studies on Hypergroups (in Hungarian) University of Debrecen, Hungary, March 31, 2011.
- Fibonacci’s Rabbits and Spectral Synthesis. (in Hungarian) University of Debrecen, Hungary, March 31, 2011.
- Spectral analysis and spectral synthesis Batz-sur-Mer, France: Plenary talk, 48th International Symposium on Functional Equations, June, 14– 20, 2010.
- Spectral Analysis on Commutative Hypergroups. The 10th Debrecen– Katowice Winter Seminar, Zamárdi, Hungary, February 3–6, 2010.
- Fourier series of mean periodic functions Budapest, Hungary: 3rd Workshop in Fourier Analysis and Related Fields, September, 17–23, 2009.
- Mean periodic functions Gargnano, Italy: 47th International Symposium on Functional Equations, June, 14–20, 2009.
- Transforms of mean periodic functions. Workshop on Dyadic Analysis and Related Areas with Applications, Dobogókő, Hungary, June 7-10, 2009.
- Mean periodic functions and Fourier transforms. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Hungary, May 7, 2009.
- The Fourier transform of mean periodic functions. Special seminar, Columbia University, New York, NY, USA, April 20, 2009.
- Functional Equations on Hypergroups Opava, Czech Republik: 46th International Symposium on Functional Equations, June, 22–29, 2008.
- Spectral analysis and spectral synthesis. Special seminar, Harvard University, Boston, Cambridge, MA, USA, March 13, 2008.
- Spectral synthesis on hypergroups. The M60 conference on the occasion of the 60st birthday of Miklós Laczkovich, Rényi Institute, Budapest, Hungary, February 22– February 24, 2008.
- Spectral synthesis on Sturm–Liouville hypergroups. The 8th Debrecen– Katowice Winter Seminar, Poroszló, Hungary, January 30– February 2, 2008.
- Spectral Synthesis Problems on Locally Compact Groups. Conference on Inequalities and Applications ’07, Noszvaj, Hungary, September, 9–15, 2007.
- Spectral Synthesis. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Hungary, April, 17, 2007.
- On Discrete Spectral Synthesis. Louisville, Kentucky, USA: 44th International Symposium on Functional Equations, May, 14–20, 2006.
- Superstability of moment functions on hypergroups. Louisville, Kentucky, USA: 44th International Symposium on Functional Equations, May, 14–20, 2006.
- Spectral Synthesis over Discrete Abelian Groups. Budapest, Hungary: Hungarian Academy of Sciences, May, 2006.
- Moment functions on Sturm–Liouville hypergroups. The 6th Debrecen– Katowice Winter Seminar, Berekfürdő, Hungary, February 1–4, 2006.
- Discrete Spectral Synthesis. Eger, Hungary: Fejér–Riesz Conference, June, 9–13, 2005.
- Polynomial Functions and Spectral Synthesis. Batz-sur-Mer, France: 43rd International Symposium on Functional Equations, May, 15–21, 2005.
- Regularity Theorems for Special Function Classes. Batz-sur-Mer, France: 43rd International Symposium on Functional Equations, Special Session, May, 15–21, 2005.
- Characterization of Polynomial Ideals. (in Hungarian) University of Debrecen, Seminar at the Institute of Mathematics, Hungary, February 17, 2005.
- Diﬀerence Equations on Polynomial Hypergroups II.. The 5th Debrecen– Katowice Winter Seminar, Bedlewo, Poland, February 2-5, 2005.
- The Singer, Not The Song… (In memoriam Jenő Erdős). (in Hungarian) University of Debrecen, Hungary, December 9, 2004.
- Partial Diﬀerence Equations and Spectral Synthesis. Opava, Czeh Republic: 42nd International Symposium on Functional Equations, June 20–27, 2004.
- Spectral Analysis and Spectral Synthesis on Polynomial Hypergroups. Budapest, Hungary: Probability Theory on Groups and Related Structures, International Conference on the occasion of Herbert Heyer’s retirement, August 2–6, 2004.
- Spectral Synthesis and Diﬀerence Equations. Seminar at the Department of Mathematics and Statistics, Sultan Qaboos University, Oman, February 18, 2004.
- Binomial Functional Equations on Polynomial Hypergroups. The 4th Debrecen–Katowice Winter Seminar, Mátraháza, Hungary, February 47, 2004.
- Spectral Synthesis on Torsion Groups. University of Debrecen, Seminar at the Institute of Mathematics, Hungary, January 22, 2004.
- Spectral Analysis and Spectral Synthesis. Seminar at the Department of Mathematics and Statistics, Sultan Qaboos University, Oman, November 19, 2003.
- Moment Functions on Hypergroups. Noszvaj, Hungary: 41st International Symposium on Functional Equations, June 8–15, 2003.
- Mean Periodic Functions. Mississippi State, MS, USA: Seminar at the Department of Mathematics and Statistics, Mississippi State University, Mississippi State, April 19, 2002.
- Spectral Synthesis. Seminar Series, Department of Mathematics, University of Louisville, Louisville, Kentucky, Spring Semester, 2002.
- Functional equations, Chebyshev polynomials, hypergroups. (in Hungarian) Debrecen, Hungary: Meeting dedicated to the 60th birthday of Professor László Losonczi, 2001.
- Hypergroups, Functional Equations. (in Hungarian) Debrecen, Hungary: 9th Síkfőkút Analysis Seminar, Institute of Mathematics and Informatics, June 15-17, 2001.
- Exponential Polynomials on Polynomial Hypergroups. Muszyna–Zlockie, Poland: 8th International Conference on Functional Equations and Inequalities, September 9–15, 2001.
- Polynomial Hypergroups and Functional Equations on Hypergroups. Sjandberg, Denmark: 39th International Symposium on Functional Equations, August 12–18, 2001.
- Conditional Expectation of Mean-periodic Functions. (in German) Dresden, Germany: Seminar talk at Technical University Dresden, May 2001.
- Mean Periodic Functions. (in Hungarian) Debrecen, Hungary: Seminar talk at Debrecen University, May 2001.
- Translation Invariant Function Spaces and Spectral Synthesis. (in Hungarian) Budapest, Hungary: Seminar talk at Budapest Technical University, April 2001.
- Functional Equations on Hypergroups. Cieszyn, Poland: 1st Katowice– Debrecen Winter Seminar on Functional Equations, February 7–10, 2001.
- On Discrete Spectral Synthesis. Noszvaj, Hungary: 38th International Symposium on Functional Equations, June 11–18, 2000.
- Stability Problems for Functional Equations. Cambridge, United Kingdom: Seminar talk at Trinity College, Cambridge University, May 2000.
- Convolution Type Functional Equations. Oxford, United Kingdom: Seminar talk at St.John’s College, Oxford University, May 2000.
- Functional Equations of Convolution Type. (in Hungarian) Budapest, Hungary: Hungarian Academy of Sciences, May 2000.
- Stability of Functional Equations. (in Hungarian) Veszprém, Hungary: Seminar of the Mathematical Institute of Veszprém University, February 2000.
- On a Functional Equation for a Two-variable Function. Muszyna, Poland: The Seventh International Conference on Functional Equations and Inequalities, September 12–18, 1999.
- Digital Filters and Functional Equations. (in Hungarian) Veszpr´em, Hungary: Meeting dedicated to the 60th birthday of Professors József Gróf and János Győrváry, 1999.
- On Discrete Spectral Synthesis. Budapest, Hungary: Functions, Series, Operators, Alexits Memorial Conference, Budapest, 1999.
- Remark on Mean-value Type Functional Equations. Huntington, West Virginia, USA: 37th International Symposium on Functional Equations, 1999.
- Exponential Polynomials and Functional Equations. (in Hungarian) Eger, Hungary: Seminar of the Eszterházy Károly Highschool, Eger, 1999.
- Discrete Spectral Synthesis. Debrecen, Hungary: 7th ”Síkfőkút Analysis Seminar”, Institute of Mathematics and Informatics, June 4-6, 1999.
- A Wiener Tauberian Theorem on Discrete Abelian Torsion Groups. (in Hungarian) Debrecen, Hungary: Conference on Analysis, Kossuth Lajos University, 1999.
- Spectral Synthesis and Functional Equations. (in German) Munich, Germany: Department of Mathematics, Technical University of Munich, 1998.
- On Convolution–type Functional Equations. (in German) Neuherberg, Germany: Workshop Harmonic Analysis and Wavelets, GSF-Forschungszentrum für Umwelt und Gesundheit, 1998.
- Exponential Polynomials and Fourier–transforms. (in German) Munich, Germany: Mathematics Seminar of the Technical University of Munich, 1998.
- Laudatio for Zoltán Daróczy. Noszvaj, Hungary: Numbers, Functions, Equations ’98, International Conference dedicated to the 60th birthday of Professors Zoltán Daróczy and Imre Kátai, 1998.
- On the Extension of Exponential Polynomials. Brno, Czech Republic: 36th International Symposium on Functional Equations, 1998.
- On Mean Periodic Functions. Graz, Austria: 35th International Symposium on Functional Equations, 1997.
- The Fourier–transform of Mean Periodic Functions. (in Hungarian) Budapest, Hungary: Seminar of the Eötvös Loránd University, Budapest, 1997.
- On the Stability of Functional Equations. (in Hungarian) Pécs, Hungary: Seminar of the Janus Pannonius University, Pécs, 1996.
- On the Stability of Linear Functional Equations. (in Hungarian) Síkfőkút, Hungary: ”In Memoriam György Szabó” Meeting, 1996.
- Hilbert Spaces. (in Hungarian) Debrecen, Hungary: Habilitation talk, Hungarian Academy of Sciences, 1995.
- On Cosine Operator Functions. Zamárdi, Hungary: 2nd Debrecen Graz Seminar, 1995.
- Characterization of Linear Operators by Stability Properties. Kuwait City, Kuwait: Mathematics Colloquium of the Department of Mathematics, Kuwait University, 1994.
- On the Stability of Homogeneous Functions. Krynica, Poland: The Fourth International Conference on Functional Equations and Inequalities, ”Stability”, 1993.
- Regularization and General Methods in the Theory of Functional Equations. Oberwolfach, Germany: 30th International Symposium on Functional Equations, 1992.
- Functional Equations and Spectral Synthesis. Kuwait City, Kuwait: Mathematics Colloquium of the Department of Mathematics, Kuwait University, 1992.
- On a Problem of M.Laczkovich. Wolfville, Nova Scotia, Canada: 29th International Symposium on Functional Equations, 1991.
- On Functional Equations Analoguous to Some Partial Diﬀerential Equations. Graz, Austria: 1st Debrecen -Graz Seminar, 1991.
- On Stability Theorems, (in Hungarian). Debrecen, Hungary: Meeting dedicated to ”Aczél -Daróczy”, 1991.
- Stability of Functional Equations in Several Variables. Graz, Austria: 28th International Symposium on Functional Equations, 1990.
- Functional Equations via Harmonic Analysis. Cosenza, Italy: Department of Mathematics, University of Calabria, 1990.
- Functional Equations via Spectral Synthesis, (seminar). Milan, Italy: Department of Mathematics, University of Milan, 1990.
- Convolution-type functional equations. Hamburg, Germany: International Congress on Mathematics for the 300th Anniversary of the Foundation of the Mathematical Society of Hamburg, 1990.
- Spectral synthesis and functional equations. Vienna, Austria: XII. Österreichischer Mathematikerkongress, 1989.
- Translation invariant subspaces and convolution-type functional equations. Bielsko-Biala, Katowice, Kraków, Poland: 27th International Symposium on Functional Equations, 1989.
- Funktionalanalytische Methoden in der Theorie der Funktionalgleichungen. Marburg, Germany: Mathematisches Institut der Universität Marburg, 1989.
- Stability of some functional equations in economics. Milan, Italy: Department of Mathematics, University of Milan, 1988.
- Stabilitätsfragen einiger Funktionalgleichungen in der Wirtschaftstheorie. (in German) Karlsruhe, Germany: Institute of Economics and Operation Research, University of Karlsruhe, 1988.
- Über die Funktionalgleichung von Levi-Civitá. (in German) Hamburg, Germany: Mathematisches Kolloquium der Universität Hamburg, 1988.
- Über einen Superstabilitätssatz. (in German) Graz, Austria: Mathematisches Kolloquium der Karl Franzens Universität, 1988.
- Über die Levi-Civitá-Funktionalgleichung. (in German) Graz, Austria: Mathematisches Kolloquium der Karl Franzens Universität, 1988.
- On a problem of S.Mazur. San Feliu de Quixols, Spain: 26th International Symposium on Functional Equations, 1988.
- On A Property of Exponential Functions. Hamburg, Germany: 25th International Symposium on Functional Equations, 1987.
- On the Extension of Local Polynomials. Bielsko-Biala, Poland: Department of Mathematics, Technical University Lódz, 1987.
- Local Polynomials and Functional Equations. Katowice, Poland: Institute of Mathematics, Silesian University, 1987.
- Extension Theorems for Functional Equations. Kraków, Poland: Institute of Mathematics, University of Mining and Metallurgy, 1987.
- On a Class of Linear Functional Equations. Szczawnicza, Poland: International Conference on Functional Equations, 1987.
- Spline Approximational Method for The Wave Equation. Varna, Bulgaria: Conference on Constructive Theory of Functions, 1987.
- On Addition Theorems. Noszvaj, Hungary: 3rd International Conference on Functional Equations and Inequalities, 1986.
- Polynomially Additive Functions. South Hadley, USA: 24th International Symposium on Functional Equations, 1986.
- Fourier Transformation und mittelperiodische Funktionen. (in German) Karlsruhe, Germany: Mathematisches Kolloquium der Universität Karlsruhe, 1986.
- Additivity -a general principle. Karlsruhe, Germany: Institute of Economics and Operation Research, University of Karlsruhe, 1986.
- Fourier Transformation und mittelperiodische Funktionen. Erlangen, Germany: Mathematisches Kolloquium der Universität Erlangen-Nürnberg, 1986.
- The Fourier Transform of Mean Periodic Functions. Graz, Austria: XI.Österreichischer Mathematikerkongress, 1985.
- Functional Equations and Transformations. Gargnano, Italy: 23rd International Symposium on Functional Equations, (special session), 1985.
- Hyers’s Theorem via Invariant Means. Gargnano, Italy: 23rd International Symposium on Functional Equations, 1985.
- Invariante Mittelwerten und der Satz von Hyers. Bern, Switzerland: Mathematisches Kolloquium der Universität Bern, 1985.
- Exponential Polynomials and Functional Equations. Oberwolfach, Germany: 22nd International Symposium of Functional Equations, 1984.
- The Fourier Transform of Exponential Polynomials. Debrecen, Hungary: International Conference on Generalized Functions, 1984.
- L
^{p}-approximation by Splines. Varna, Bulgaria: Conference on Constructive Theory of Functions, 1984. - Almost Periodicity in Functional Equations. Konolﬁngen, Switzerland: 21st International Symposium on Functional Equations, 1983.
- Regularit¨atseigenschaften von Exponentialpolynomen. Graz, Austria: Mathematisches Kolloquium der Karl Franzens Universität, 1983.
- Functional Diﬀerential Equations by Splines. Russe, Bulgaria: 2nd Conference on Diﬀerential Equations and Applications, 1982.
- Fastperiodische Funktionen und Funktionalgleichungen. (in German) Rostock, GDR: Mathematisches Kolloquium der Wilhelm Pieck Universit¨at, 1982.
- Exponential Polynomials. Oberwolfach, Germany: 20th International Symposium on Functional Equations, 1980.
- Functional Equations on Topological Groups. Debrecen, Hungary: 2nd International Conference on Functional Equations and Inequalities, 1979.
- Polynomials on Groups. Leibnitz, Austria: 18th International Symposium on Functional Equations, 1978.