1. I. N. Abramovskii, “Groups in which the subgroup lattices is a relatively complemented lattice,” Algebra Logika. Seminar, 6(1):5–8 (1967).
2. A. Ya. Aizenshtat, “Regular endomorphism semigroups of ordered sets,” Uch. Zap. Leningrad. Gos. Ped. Inst. im. A. I. Gertsena, 387:3–11 (1968).
3. S. A. Anishchenko, “Representation of certain modular lattices by subgroup lattices,” Mat. Zap. Krasnoyarsk. Ped. Inst., 1:1–21 (1965).
4. A. F. Bravtsev, “Congruences of the direct product of algebras,” Algebra Logika. Seminar, 6 (1):39–43 (1967).
5. I. I. Valutse, “Some aspects of the theory of unary algebras,” in: Abstracts of the Reports of the Second Scientific Engineering Conference of the Kishniev Polytechnic Institute [in Russian], Kishniev (1966), 229 pp.