@article{NSJOM_1977_7_Nonea_5,
     author = {{\CYRYA}{\cyra}{\cyrn}{\cyre}{\cyrz} 

 {\CYRU}{\cyrsh}{\cyra}{\cyrn} and {\CYRZH}{\cyra}{\cyrr}{\cyrk}{\cyro}{\cyrv} {\CYRD}{\cyro}{\cyrb}{\cyrr}{\cyri}{\cyrv}{\cyro}{\cyrishrt}},
     title = {{\CYRO}{\cyrb} {\cyro}{\cyrd}{\cyrn}{\cyro}{\cyrishrt} 

 {\cyrs}{\cyri}{\cyrs}{\cyrt}{\cyre}{\cyrm}{\cyre} {\cyrf}{\cyru}{\cyrn}{\cyrk}{\cyrc}{\cyri}{\cyro}{\cyrn}{\cyra}{\cyrl}{\cyrsftsn}{\cyrn}{\cyrery}{\cyrh} 

 {\cyru}{\cyrr}{\cyra}{\cyrv}{\cyrn}{\cyre}{\cyrn}{\cyri}{\cyrishrt} 

 {\cyro}{\cyrb}{\cyrsh}{\cyre}{\cyrishrt} 

 {\cyra}{\cyrs}{\cyrs}{\cyro}{\cyrc}{\cyri}{\cyra}{\cyrt}{\cyri}{\cyrv}{\cyrn}{\cyro}{\cyrs}{\cyrt}{\cyri} {\cyrn}{\cyra} {\cyra}{\cyrl}{\cyrg}{\cyre}{\cyrb}{\cyrr}{\cyre} {\cyri}{\cyrn}{\cyrf}{\cyri}{\cyrn}{\cyri}{\cyrt}{\cyra}{\cyrr}{\cyrn}{\cyrery}{\cyrh} 

 {\cyrk}{\cyrv}{\cyra}{\cyrz}{\cyri}{\cyrg}{\cyrr}{\cyru}{\cyrp}{\cyrp}},
     journal = {Novi Sad Journal of Mathematics},
     pages = {37-44},
     publisher = {mathdoc},
     volume = {7},
     year = {1977},
     url = {http://geodesic.mathdoc.fr/item/NSJOM_1977_7_Nonea_5/}
}