Normality Conditions for Quasinormal Subgroups in Finite Groups. Rudolf Maier — 1971 Mathematische Zeitschrift
The Embedding of Quasinormal Subgroups in Finite Groups. Peter Schmid; Rudolf Maier — 1973 Mathematische Zeitschrift
𝔛 C -elements in groups and Dietzmann classes. Maier, Rudolf; Rogério, José Robério — 1999 Beiträge zur Algebra und Geometrie