@article{ZVMMF_1969_9_1_a14,
     author = {A. P. Petrov and A. V. Khovanskii},
     title = {Lower bound of the error in the solution of operator equations in compact spaces},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {194--201},
     publisher = {mathdoc},
     volume = {9},
     number = {1},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1969_9_1_a14/}
}