Index transforms of multidimensional cyclic convolutions and discrete Fourier transforms. - Josef Hekrdla (IEEE Trans. Acoust. Speech Signal Process., 1986)

Equivalence of Analogue and Discrete Systems. - Josef Hekrdla (ASST, 1990)

Two Approaches to Fuzzy Propositional Logics. - Josef Hekrdla; Erich-Peter Klement; Mirko Navara (J. Multiple Valued Log. Soft Comput., 2003)