@article{SF_1978__16_134289,
     author = {F.W. Roush and K.H. Kim},
     title = {On groups in varieties of semigroups.},
     journal = {Semigroup forum},
     pages = {201--202},
     year = {1978},
     volume = {16},
     zbl = {0398.20060},
     url = {http://geodesic.mathdoc.fr/item/SF_1978__16_134289/}
}