@article{DE_1972_8_7_a12,
     author = {V. E. Shatalov},
     title = {Dirichlet series that are composed of the eigenvalues of boundary value problems for an arbitrary second order elliptic differential operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1267--1282},
     publisher = {mathdoc},
     volume = {8},
     number = {7},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_7_a12/}
}