@article{DAN_1975_221_1_a2,
     author = {N. L. Vasilevskii and E. V. Gutnikov},
     title = {On the symbol of operators forming finite-dimensional algebras},
     journal = {Doklady Akademii Nauk},
     pages = {18--21},
     publisher = {mathdoc},
     volume = {221},
     number = {1},
     year = {1975},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1975_221_1_a2/}
}