BerezanskyY. M., GorbachukV. I., GorbachukM. L., KorolyukV. S., MitropolskiyY. A., SamoilenkoA. M., & TarasovV. G. (1995). On the 60th birthday of Leonid Pavlovich Nizhnik. Ukrains’kyi Matematychnyi Zhurnal, 47(10), 1416–1417. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/5536