“…The results presented here spring from the classical results of Schmidt [13] about the structure of the minimal non-nilpotent groups and later developments from them ( [12], [2], [3], [9], [10]). Schmidt proved that if all the maximal subgroups of a group G are nilpotent, then G is soluble, and that, in addition, if G is not nilpotent, |G| has exactly two distinct prime factors, G has a normal Sylow subgroup and a cyclic non-normal Sylow subgroup.…”