1. Chih-Han Sah, “On a generalization of finite nilpotent groups,” Math. Zeit.,68, 189–204 (1957).
2. P. Hall, “On the Sylow systems of a solvable group,” Proc. London Math, Soc.,43, 316–323 (1937).
3. V. M. Busarkin and Yu. M. Gorchakov, Finite Decomposable Groups, Nauka, Moscow (1968).
4. V. V. Tsybulenko, “Finite groups with certain systems of n-commuting Sylow subgroups,” in: Groups with Subgroups Having Given Properties, Instituta Matematiki Akad. Nauk UkrSSR, Kiev (1973).
5. R. W. Carter, “Nilpotent self-normalizing subgroups of a soluble group,” Math. Zeit.,75, 136–139 (1961).