@article{GDZPPN002413272,
title = {Normal Subgroups of M-Groups Need Not Be M-Groups.},
journal = {Mathematische Zeitschrift},
volume = {135},
year = {1973},
pages = {313-318},
zbl = {0255.20007},
url = {http://dml.mathdoc.fr/item/GDZPPN002413272}
}
Dade, Everett C. Normal Subgroups of M-Groups Need Not Be M-Groups.. Mathematische Zeitschrift, Tome 135 (1973) pp. 313-318. http://gdmltest.u-ga.fr/item/GDZPPN002413272/