@article{IVM_1985_3_a10,
     author = {I. I. Ryabcev},
     title = {On the general theory of perfect operators},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {76--81},
     publisher = {mathdoc},
     number = {3},
     year = {1985},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1985_3_a10/}
}