@article{zu219906,
          volume = {23},
          number = {1},
           title = {???????? ?????????????? ?????????? ????? ? ?????? ? ?????????? ?????????},
          author = {?. ?. ??????? and ?. ?. ??????? and ?. ?. ??????},
            year = {1987},
           pages = {159--161},
         journal = {?????????????? ?????????},
             url = {http://eprints.zu.edu.ua/19906/}
}