@article{SLC_1988_19_a18,
     author = {Volkmar Welker},
     title = {Permutabilit\"aten kleiner endlicher {Gruppen}},
     journal = {S\'eminaire lotharingien de combinatoire},
     year = {1988},
     volume = {19},
     url = {http://geodesic.mathdoc.fr/item/SLC_1988_19_a18/}
}