RYBAK, I.V. Monotone and conservative difference schemes for elliptic equations with mixed derivatives. Mathematical Modelling and Analysis, [S. l.], v. 9, n. 2, p. 169–178, 2004. DOI: 10.3846/13926292.2004.9637250. Disponível em: https://journals.vilniustech.lt/index.php/MMA/article/view/9725. Acesso em: 3 jul. 2025.