1. B. Huppert, Endliche Gruppen I (Springer, Berlin, 1967).
2. R. Bastos and P. Shumyatsky, “A sufficient condition for nilpotency of the commutator subgroup,” Sib. Math. J. 57 (5), 762–763 (2016).
3. V. S. Monakhov, “The nilpotency criterion for the commutator subgroup of a finite group,” Probl. Fiz., Mat. Tekhn., No. 3(32), 58–60 (2017).
4. O. Yu. Schmidt, “Groups all of whose subgroups are special,” Mat. Sb. 31 (3–4), 366–372 (1924).
5. V. S. Monakhov, “Schmidt subgroups, their existence, and some applications,” in Proceedings of the Ukrainian Mathematical Congress, Kiev, Ukraine, 2001 (Izd. Inst. Matem., Kiev, 2001), Sect. 1, pp. 81–90.