@article{NSJOM_1987_17_2a_1,
     author = {Michalski J.},
     title = {Associated k-groups of n-groups},
     journal = {Novi Sad Journal of Mathematics},
     pages = {9-30},
     year = {1987},
     volume = {17},
     number = {2},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1987_17_2a_1/}
}