1. R. Dedekind, “Uber Gruppen, deren summtliche Teiler Normalteiler sind,” Math. Ann., 48, 548–561 (1897).
2. G. A. Miller and H. C. Moreno, “Non-abelian groups in which every subgroup is abelian,” Trans. Amer. Math. Soc., 4, 389–404 (1903).
3. O. Yu. Shmidt, “Groups all subgroups of which are special,” Mat. Sb., 31, No.3, 366–372 (1924).
4. B. H. Neumann, “Groups with finite classes of conjugate subgroups,” Math. Z., No. 1, 76–96 (1955).
5. I. I. Eremin, “Groups with finite classes of conjugate Abelian subgroups,” Mat. Sb., 47, No.1, 45–54 (1959).