@article{GDZPPN002410133, title = {Groups All of Whose Subgroups are M-Groups.}, journal = {Mathematische Zeitschrift}, volume = {129}, year = {1972}, pages = {73-78}, zbl = {0248.20008}, url = {http://dml.mathdoc.fr/item/GDZPPN002410133} }
Winter, David L.; F., Murphy Paul. Groups All of Whose Subgroups are M-Groups.. Mathematische Zeitschrift, Tome 129 (1972) pp. 73-78. http://gdmltest.u-ga.fr/item/GDZPPN002410133/