@article{MZM_1997_62_5_a10,
     author = {Yu. S. Kolesov},
     title = {Stability properties of cycles and tori of a simplest nonresonant wave-type equation},
     journal = {Matemati\v{c}eskie zametki},
     pages = {744--750},
     year = {1997},
     volume = {62},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1997_62_5_a10/}
}