@article{SM_1971_13_1_a6,
     author = {V. \`E. Lyantse},
     title = {Completely regular perturbation of a~continuous {spectrum.~II}},
     journal = {Sbornik. Mathematics},
     pages = {137--154},
     year = {1971},
     volume = {13},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1971_13_1_a6/}
}