1. Belonogov, V.A.: Finite groups with three classes of maximal subgroups. Math. Sb. 131, 225–239 (1986)
2. Gorenstein, D.: Finite groups. Harper & Row, New York (1968)
3. Huppert, B.: Endliche Gruppen I vol. 134 of Grund Math Wiss. Springer, Berlin (1967)
4. Lu, J.K., Pang, L.N., Zhong, X.G.: Finite groups with non-nilpotent maximal subgroups. Monatsh. Math. 171, 425–431 (2013)
5. Meng, W., Lu, J.K.: Lower bounds on conjugacy classes of non-nilpotent subgroups in a finite group. JAA 14, 1550039 (2015)