TAO, Z.-L. Frequency-amplitude relationship of the Duffing-harmonic oscillator. Topological Methods in Nonlinear Analysis, [S. l.], v. 31, n. 2, p. 279–285, 2008. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2008.019. Acesso em: 22 jul. 2024.