@article{NSJOM_1987_17_1a_13,
     author = {Vojvodi\'c Gradimir and \v{S}e\v{s}elja Branimir},
     title = {L-valued congruences and {L-valued} 

 normal subgroups},
     journal = {Novi Sad Journal of Mathematics},
     pages = {201-207},
     publisher = {mathdoc},
     volume = {17},
     number = {1},
     year = {1987},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1987_17_1a_13/}
}