@article{DAN_1957_113_5_a13,
     author = {E. A. Troitskaya},
     title = {Recourse to the general theory of approximation methods in investigating the problem of determination of characteristic 
},
     journal = {Doklady Akademii Nauk},
     pages = {998--1001},
     publisher = {mathdoc},
     volume = {113},
     number = {5},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_113_5_a13/}
}