@article{NSJOM_1987_17_2a_7,
     author = {{\CYRYA}{\cyra}{\cyrn}{\cyre}{\cyrz} 

 {\CYRU}{\cyrsh}{\cyra}{\cyrn}},
     title = {{\CYRCH}{\cyra}{\cyrs}{\cyrt}{\cyri}{\cyrch}{\cyrn}{\cyrery}{\cyre} {{\CYRA}t-{\cyrg}{\cyrr}{\cyru}{\cyrp}{\cyrp}{\cyro}{\cyri}{\cyrd}{\cyrery}}},
     journal = {Novi Sad Journal of Mathematics},
     pages = {109-127},
     publisher = {mathdoc},
     volume = {17},
     number = {2},
     year = {1987},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1987_17_2a_7/}
}