@article{ZVMMF_2004_44_12_a1,
     author = {A. N. Pankratov},
     title = {On algebraic operations over series of orthogonal functions},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {2121--2127},
     publisher = {mathdoc},
     volume = {44},
     number = {12},
     year = {2004},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_2004_44_12_a1/}
}