System theory. Complex function theory. System theory. Partial difference equations.

• J. Gregor and J. Tišer "On Hadamard Powers of Hurwitz Polynomials", Math. of Control, Signals, and Systems , 1998, No. 11. pp. 372–378.
• J. Gregor "The Cauchy Problem for Partial Difference Equations ", Acta Appl. Math., 1998, Vol. 53., No. 3. pp. 247–263.
• J. Gregor "Towards a General Theory of Discrete Systems", in P. M. Frank (Editor) Advances in Control, Springer Verlag, London, 1999.
• J. Gregor "Difference Equations and n-D discrete Systems" In: Proceedings of the Fifteenth International Symposium on Mathematical Theory of Networks and Systems [CD-ROM] . Notre Dame: University of Notre Dame, 2002.
• J. Gregor "Continued Fractions and 2D Hurwitz Polynomials" In: Multidimensional Systems and Signal Processing. 2002, vol. 13, no. 2, p. 187–199. ISSN 0923-6082.
• J. Gregor "Stability of Non-Convolutional n-D Linear Systems", Trans. IEEE Circuits & Systems, I, 2002, Vol. 19, No. 12, December, pp. 1773–1781.
• J. Gregor "Partial difference equations and the maximum principle", WSEAS Trans.on Math, Issue I, Vol. 3, January 2004, pp. 192–197.
• J. Gregor "The maximum principle and growth estimates for partial difference equations", Aequationes Mathematicae, Vol. 79 (2006), pp. 86–99.

• Czech Technical University in Prague