@article{ZVMMF_1971_11_1_a22,
     author = {S. A. Abramov},
     title = {Operating above certain expressions},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {248--257},
     publisher = {mathdoc},
     volume = {11},
     number = {1},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1971_11_1_a22/}
}