1. An eight-term exact sequence associated with a group extension;Cheng;Michigan Math. J.,1980
2. On exact sequences in homology associated with a group extension;Gut;J. Pure Appl. Algebra,1976
3. A Course in Homological Algebra;Hilton,1971
4. Verschra¨nkten-fache Erweiterungen von Gruppen und Cohomologie;Huebschmann,1977
5. Group extensions, crossed pairs and an eight term exact sequence;Huebschmann;J. Reine Angew. Math.,1981