@article{GDZPPN001251848, title = {General mutants in semigroups.}, journal = {Semigroup forum}, volume = {12}, year = {1976}, pages = {297-300}, zbl = {0354.20050}, url = {http://dml.mathdoc.fr/item/GDZPPN001251848} }
Kim, K. H.; Roush, F. General mutants in semigroups.. Semigroup forum, Tome 12 (1976) pp. 297-300. http://gdmltest.u-ga.fr/item/GDZPPN001251848/