@article{GDZPPN002409844, title = {On Equivalence of Finite Group Extensions.}, journal = {Mathematische Zeitschrift}, volume = {121}, year = {1971}, pages = {191-200}, zbl = {0224.20023}, url = {http://dml.mathdoc.fr/item/GDZPPN002409844} }
Zassenhaus, Hans; Johnson, Charles E. On Equivalence of Finite Group Extensions.. Mathematische Zeitschrift, Tome 121 (1971) pp. 191-200. http://gdmltest.u-ga.fr/item/GDZPPN002409844/