Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{CMUC_1967__8_3_a6, author = {Havel, V\'aclav}, title = {Nets and groupoids}, journal = {Commentationes Mathematicae Universitatis Carolinae}, pages = {435--451}, publisher = {mathdoc}, volume = {08}, number = {3}, year = {1967}, mrnumber = {0223956}, zbl = {0162.24001}, language = {en}, url = {http://geodesic.mathdoc.fr/item/CMUC_1967__8_3_a6/} }
Havel, Václav. Nets and groupoids. Commentationes Mathematicae Universitatis Carolinae, Tome 08 (1967) no. 3, pp. 435-451. http://geodesic.mathdoc.fr/item/CMUC_1967__8_3_a6/