A chain of Kurosh may have an arbitrary finite length Konstantin Igorevich Beidar — 1982 Czechoslovak Mathematical Journal
Идемпотенты в кольцах с полиномиальным тождеством Konstantin Igorevich Beidar — 1981 Commentationes Mathematicae Universitatis Carolinae
Additive radicals Konstantin Igorevich Beidar; Katarina Trokanová-Salavová — 1989 Czechoslovak Mathematical Journal