@article{VMUMM_1989_6_a2,
     author = {B. Zekovi\'c},
     title = {Universal covering rings and their radicals},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {14--17},
     publisher = {mathdoc},
     number = {6},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1989_6_a2/}
}