1. Der Kern, eine charakterische Untergruppe;Baer;Compos. Math.,1934
2. Generalised norms in finite soluble groups;Ballester Bolinches;J. Algebra,2014
3. Power automorphisms of a group;Cooper;Math. Z.,1968
4. M. De Falco, F. de Giovanni, L.A. Kurdachenko, C. Musella, The metanorm, a characteristic subgroup: embedding properties, submitted for publication.
5. Groups whose finite homomorphic images are metahamiltonian;De Falco;Comm. Algebra,2009