@article{GDZPPN00125135X, title = {Continuously factorable groupoids.}, journal = {Semigroup forum}, volume = {12}, year = {1976}, pages = {251-264}, zbl = {0327.22002}, url = {http://dml.mathdoc.fr/item/GDZPPN00125135X} }
Sigmon, K.; Hu, H.-T. Continuously factorable groupoids.. Semigroup forum, Tome 12 (1976) pp. 251-264. http://gdmltest.u-ga.fr/item/GDZPPN00125135X/