@article{GDZPPN002298066, title = {Structures Quasi-Quotient.}, journal = {Mathematische Annalen}, volume = {174}, year = {1967}, pages = {293-364}, zbl = {0248.18007}, url = {http://dml.mathdoc.fr/item/GDZPPN002298066} }
EHRESMANN, CH. Structures Quasi-Quotient.. Mathematische Annalen, Tome 174 (1967) pp. 293-364. http://gdmltest.u-ga.fr/item/GDZPPN002298066/