@article{01538434, title = {A proper subclass of MacLane's class }, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {22}, year = {1999}, pages = {463-468}, doi = {10.1155/S0161171299224635}, zbl = {0966.30025}, language = {en}, url = {http://dml.mathdoc.fr/item/01538434} }
Hamdan, May. A proper subclass of MacLane's class . International Journal of Mathematics and Mathematical Sciences, Tome 22 (1999) pp. 463-468. doi : 10.1155/S0161171299224635. http://gdmltest.u-ga.fr/item/01538434/