BAK, S. N.; PANKOV, A. A. On the dynamical equations of a system of linearly coupled nonlinear oscillators. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 6, p. 723–729, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3490. Acesso em: 5 dec. 2025.