@article{MAN_1972__198_162291,
     author = {Hans J. Zassenhaus},
     title = {On {L-Semi-Groups.}},
     journal = {Mathematische Annalen},
     pages = {13--22},
     publisher = {mathdoc},
     volume = {198},
     year = {1972},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/MAN_1972__198_162291/}
}