@article{MZ_1981__177_173062,
     author = {Martin Isaacs},
     title = {Primitive {Characters,} {Normal} {Subgroups,} and {M-Groups.}},
     journal = {Mathematische Zeitschrift},
     pages = {267--284},
     publisher = {mathdoc},
     volume = {177},
     year = {1981},
     zbl = {0475.20007},
     url = {http://geodesic.mathdoc.fr/item/MZ_1981__177_173062/}
}