@article{ZVMMF_1983_23_5_a19,
     author = {S. N. Kukudzhanov},
     title = {Optimal approximations in the eigenvalue problem for the {Ritz} and {Bubnov{\textendash}Galerkin} methods},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {1230--1233},
     publisher = {mathdoc},
     volume = {23},
     number = {5},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1983_23_5_a19/}
}