@article{NSJOM_1987_17_2a_4,
     author = {{\CYRYA}{\cyra}{\cyrn}{\cyre}{\cyrz} 

 {\CYRU}{\cyrsh}{\cyra}{\cyrn}},
     title = {{\CYRO}{\cyrb} {\cyro}{\cyrd}{\cyrn}{\cyro}{\cyrm} 

 {\cyro}{\cyrb}{\cyro}{\cyrb}{\cyrshch}{\cyre}{\cyrn}{\cyri}{\cyryu} {\cyrr}{\cyre}{\cyrsh}{\cyre}{\cyrt}{\cyro}{\cyrk}},
     journal = {Novi Sad Journal of Mathematics},
     pages = {57-63},
     publisher = {mathdoc},
     volume = {17},
     number = {2},
     year = {1987},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1987_17_2a_4/}
}