1. S. N. Chernikov, Groups with Given Properties of a System of Subgroups [in Russian], Nauka, Moscow (1980).
2. V. I. Senashov, ?Characterization of layer-finite groups in the class of periodic groups,? Algeb. Logika,24, No. 5, 608?617 (1985).
3. V. I. Senashov, ?Characterization of layer-finite groups,? Algeb. Logika,28, No. 6, 687?704 (1989).
4. O. Yu. Shmidt, ?Groups, all subgroups of which are special,? Mat. Sb.,31, 366?372 (1924).
5. V. P. Shunkov, ?On a certain class of p-groups,? Algeb. Logika,9, No. 4, 484?496 (1970).