@article{2325, author = {Kleinfeld, Erwin}, title = {Rings of $(\gamma ,\delta )$ type}, journal = {Portugaliae mathematica}, volume = {18}, year = {1959}, pages = {107-110}, zbl = {0090.02402}, mrnumber = {0110738}, language = {en}, url = {http://dml.mathdoc.fr/item/2325} }
Kleinfeld, Erwin. Rings of $(\gamma ,\delta )$ type. Portugaliae mathematica, Tome 18 (1959) pp. 107-110. http://gdmltest.u-ga.fr/item/2325/