@article{02033402,
title = {On congruence classes of },
journal = {Novi Sad Journal of Mathematics},
volume = {28},
year = {1998},
pages = {75-89},
zbl = {1030.20503},
language = {en},
url = {http://dml.mathdoc.fr/item/02033402}
}
Ušan, Janez. On congruence classes of . Novi Sad Journal of Mathematics, Tome 28 (1998) pp. 75-89. http://gdmltest.u-ga.fr/item/02033402/