@article{IVM_1977_7_a6,
     author = {L. E. Isaev},
     title = {Operators of class $C_0$},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {54--56},
     publisher = {mathdoc},
     number = {7},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1977_7_a6/}
}