@article{DAN_1989_308_1_a0,
     author = {K. Kh. Boimatov},
     title = {Eigenvalues of elliptic differential operators in},
     journal = {Doklady Akademii Nauk},
     pages = {11--14},
     publisher = {mathdoc},
     volume = {308},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_308_1_a0/}
}