@article{GDZPPN00239894X, title = {An Example of Core-Free Quasinormal Subgroups of p-Groups.}, journal = {Mathematische Zeitschrift}, volume = {99}, year = {1967}, pages = {226-227}, zbl = {0189.31702}, url = {http://dml.mathdoc.fr/item/GDZPPN00239894X} }
Thompson, John G. An Example of Core-Free Quasinormal Subgroups of p-Groups.. Mathematische Zeitschrift, Tome 99 (1967) pp. 226-227. http://gdmltest.u-ga.fr/item/GDZPPN00239894X/