@article{AUCMP_1997_38_2_a2,
     author = {Ponomarev, S. P.},
     title = {On some characterizations of quasiregularity},
     journal = {Acta Universitatis Carolinae. Mathematica et Physica},
     pages = {13--18},
     year = {1997},
     volume = {38},
     number = {2},
     mrnumber = {1614027},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/AUCMP_1997_38_2_a2/}
}