@article{DAN_1987_294_6_a6,
     author = {A. M. Krasnosel'skii},
     title = {Directed corrections in the method of harmonic balance},
     journal = {Doklady Akademii Nauk},
     pages = {1314--1318},
     publisher = {mathdoc},
     volume = {294},
     number = {6},
     year = {1987},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1987_294_6_a6/}
}