Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{CMUC_1983__24_4_a4, author = {P{\l}onka, Jerzy}, title = {Subdirectly irreducible groupoids in some varieties}, journal = {Commentationes Mathematicae Universitatis Carolinae}, pages = {631--645}, publisher = {mathdoc}, volume = {24}, number = {4}, year = {1983}, mrnumber = {738559}, zbl = {0543.08007}, language = {en}, url = {http://geodesic.mathdoc.fr/item/CMUC_1983__24_4_a4/} }
Płonka, Jerzy. Subdirectly irreducible groupoids in some varieties. Commentationes Mathematicae Universitatis Carolinae, Tome 24 (1983) no. 4, pp. 631-645. http://geodesic.mathdoc.fr/item/CMUC_1983__24_4_a4/