@article{SF_1975__10_134109,
     author = {B.M. Schein},
     title = {A new proof of the {McAlister} },
     journal = {Semigroup forum},
     pages = {185--188},
     year = {1975},
     volume = {10},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SF_1975__10_134109/}
}