@article{IM2_1972_6_1_a7,
     author = {Yu. N. Frolov},
     title = {On a~uniqueness theorem},
     journal = {Izvestiya. Mathematics},
     pages = {241--248},
     year = {1972},
     volume = {6},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1972_6_1_a7/}
}