@article{MZ_1972__124_171658, author = {David L. Winter and Murphy Paul F.}, title = {Groups {All} of {Whose} {Subgroups} are {M-Groups.}}, journal = {Mathematische Zeitschrift}, pages = {73--78}, publisher = {mathdoc}, volume = {124}, year = {1972}, zbl = {0248.20008}, url = {http://geodesic.mathdoc.fr/item/MZ_1972__124_171658/} }