Dmytro Yakovych Petryna (on his 70 th birthday) - Gorbachuk, M. L.; Lukovsky, I. O.; Marchenko, V. O.; Mitropolskiy, Yu. A.; Pastur, L. A.; Samoilenko, A. M.; Skrypnik, I. V.; Khruslov, E. Ya. (Ukrains’kyi Matematychnyi Zhurnal, 2004)