@article{MZ_1974__137_172061,
     author = {Kenneth K. Hickin and Richard E. Phillips},
     title = {Joins of {Subnormal} {Subgroups} are {Serial.}},
     journal = {Mathematische Zeitschrift},
     pages = {129--130},
     publisher = {mathdoc},
     volume = {137},
     year = {1974},
     zbl = {0284.20032},
     url = {http://geodesic.mathdoc.fr/item/MZ_1974__137_172061/}
}