1. A. G. Kurosh, The Theory of Groups (Nauka, Moscow, 1967; 2nd English transl., 2 volumes, Chelsea Publishing Co., New York, 1960).
2. A. I. Starostin, “On Frobenius groups,” Ukrain. Mat. Zh. 23 (5), 629–639 (1971) [in Russian].
3. A. I. Sozutov and V. P. Shunkov, “On a generalization of Frobenius’ theorem to infinite groups,” Mat. Sb. 100 (142) (4(8)), 495–506 (1976) [Math. USSR-Sb. 29 (4), 441–451 (1976)].
4. V. P. Shunkov, “A certain generalization of Freobenius’ theorem to periodic groups,” Algebra Logika 6 (3), 113–124 (1967) [in Russian].
5. V. P. Shunkov, “Periodic groups with an almost regular involution,” Algebra Logika 11 (4), 470–493 (1972) [in Russian].