@article{1256052950, author = {Klein, Aaron}, title = {Relations in categories}, journal = {Illinois J. Math.}, volume = {14}, number = {4}, year = {1970}, pages = { 536-550}, language = {en}, url = {http://dml.mathdoc.fr/item/1256052950} }
Klein, Aaron. Relations in categories. Illinois J. Math., Tome 14 (1970) no. 4, pp. 536-550. http://gdmltest.u-ga.fr/item/1256052950/