NICOMEDES, W. L.; BATHE, K.-J.; MOREIRA, F. J. S.; MESQUITA, R. C. The method of finite spheres in acoustic wave propagation through nonhomogeneous media: Inf-sup stability conditions. Vietnam Journal of Mechanics, Hanoi, Vietnam, v. 42, n. 3, p. 209–237, 2020. DOI: 10.15625/0866-7136/15336. Disponível em: https://vjs.ac.vn/index.php/vjmech/article/view/15336. Acesso em: 25 apr. 2024.