FADHEL, Fadhel S; KHAYOON, Isam H. Variational Approach for Solving the Ponds Seepage Problem. Al-Nahrain Journal of Science, [S. l.], v. 21, n. 3, p. 139–145, 2018. Disponível em: https://anjs.edu.iq/index.php/anjs/article/view/1754. Acesso em: 22 may. 2026.