@article{MZ_1962__79_170076,
     author = {Helmut Wielandt},
     title = {Subnormale {H\"ullen} in {Permutationsgruppen.}},
     journal = {Mathematische Zeitschrift},
     pages = {381--388},
     year = {1962},
     volume = {79},
     zbl = {0104.24901},
     url = {http://geodesic.mathdoc.fr/item/MZ_1962__79_170076/}
}