@article{DAN_1984_278_4_a3,
     author = {I. I. Gasanov and A. D. Rikun},
     title = {Necessary and sufficient conditions for uniextremality in},
     journal = {Doklady Akademii Nauk},
     pages = {786--789},
     year = {1984},
     volume = {278},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1984_278_4_a3/}
}