@article{02116312, title = {Special morphisms of groupoids.}, journal = {Novi Sad Journal of Mathematics}, volume = {32}, year = {2002}, pages = {23-36}, zbl = {1053.20048}, language = {en}, url = {http://dml.mathdoc.fr/item/02116312} }
Ivan, Gheorghe. Special morphisms of groupoids.. Novi Sad Journal of Mathematics, Tome 32 (2002) pp. 23-36. http://gdmltest.u-ga.fr/item/02116312/