@article{DE_1981_17_9_a6,
     author = {Yu. S. Kolesov},
     title = {The amplitude method for constructing multifrequency oscillations of nonlinear systems with delay},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1596--1602},
     publisher = {mathdoc},
     volume = {17},
     number = {9},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_9_a6/}
}