Procedure of construction of an asymptotic solution of the Cauchy problem in the investigation of two-frequency models of oscillations in systems with distributed parameters. Neliniini Kolyvannya, [S. l.], v. 2, n. 3, p. 352–363, 1999. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/70. Acesso em: 22 jan. 2026.