HE, Ji-Huan. A parametrized variational principle of nonlinear piezoelectricity. Computer Assisted Methods in Engineering and Science, [S. l.], v. 10, n. 3, p. 263–269, 2023. Disponível em: https://cames3.ippt.pan.pl/index.php/cames/article/view/1074. Acesso em: 12 jan. 2025.