Approximate Nonlinear Self-Adjointness and Approximate Conservation Laws of the Gardner Equation. Punjab University Journal of Mathematics, [S. l.], v. 49, n. 1, p. 24–29, 2017. Disponível em: https://pujm.pu.edu.pk/index.php/pujm/article/view/81. Acesso em: 29 jun. 2025.