@article{01751250, title = {Subgroups of finite index in an additive group of a ring.}, journal = {International Journal of Mathematics and Mathematical Sciences}, volume = {25}, year = {2001}, pages = {83-89}, doi = {10.1155/S0161171201010274}, zbl = {1016.16011}, language = {en}, url = {http://dml.mathdoc.fr/item/01751250} }
Mojdeh, Doostali; Hashemi, S.Hassan. Subgroups of finite index in an additive group of a ring.. International Journal of Mathematics and Mathematical Sciences, Tome 25 (2001) pp. 83-89. doi : 10.1155/S0161171201010274. http://gdmltest.u-ga.fr/item/01751250/