Voir la notice de l'article provenant de la source Czech Digital Mathematics Library
@article{ARM_1981__17_4_a3, author = {Michalski, Jacek}, title = {Covering $k$-groups of $n$-groups}, journal = {Archivum mathematicum}, pages = {207--226}, publisher = {mathdoc}, volume = {17}, number = {4}, year = {1981}, mrnumber = {672660}, zbl = {0478.20045}, language = {en}, url = {http://geodesic.mathdoc.fr/item/ARM_1981__17_4_a3/} }
Michalski, Jacek. Covering $k$-groups of $n$-groups. Archivum mathematicum, Tome 17 (1981) no. 4, pp. 207-226. http://geodesic.mathdoc.fr/item/ARM_1981__17_4_a3/