New Proofs of Monotonicity of Period Function for Cubic Elliptic Hamiltonian. Journal of Nonlinear Modeling and Analysis, [S. l.], v. 1, n. 3, p. 301–305, 2024. DOI: 10.12150/jnma.2019.301. Disponível em: https://global-sci.com/index.php/jnma/article/view/13524. Acesso em: 6 dec. 2025.