ANDREEVA, N. V.; SEROV, N. I.; TULUPOVA, L. O. $Q$-conditional symmetry of a nonlinear two-dimensional heat-conduction equation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 52, n. 6, p. 846–849, 2000. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4481. Acesso em: 27 apr. 2025.