KHAN, M. M. U. R.; SAHA, G. Analytical Solution of Liénard Differential Equation using Homotopy Perturbation Method. GANIT: Journal of Bangladesh Mathematical Society, [S. l.], v. 39, p. 87–100, 2019. DOI: 10.3329/ganit.v39i0.44160. Disponível em: https://www.banglajol.info/index.php/GANIT/article/view/44160. Acesso em: 28 mar. 2024.