@article{DE_1994_30_1_a21,
     author = {V. A. Mikhailets},
     title = {Distribution of the eigenvalues of finite multiplicity of {Neumann} extensions of an elliptic operator},
     journal = {Differencialʹnye uravneni\^a},
     pages = {178--179},
     publisher = {mathdoc},
     volume = {30},
     number = {1},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1994_30_1_a21/}
}