@article{ZVMMF_1987_27_12_a1,
     author = {V. V. Ditkin},
     title = {An iterative method for solving an eigenvalue problem in the case of a multiple spectrum},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {1771--1779},
     publisher = {mathdoc},
     volume = {27},
     number = {12},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1987_27_12_a1/}
}