NIKITIN, A. G.; POPOVICH, R. O. Group Classification of Nonlinear Schrödinger Equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 53, n. 8, p. 1053–1060, 2001. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4326. Acesso em: 6 dec. 2025.