NICOMEDES, Williams L.; BATHE, Klaus-Jürgen; MOREIRA, Fernando J. S.; MESQUITA, Renato C. The method of finite spheres in acoustic wave propagation through nonhomogeneous media: Inf-sup stability conditions. <b>Vietnam Journal of Mechanics</b>, Hanoi, Vietnam, v. 42, n. 3, p. 209–237, 2020. DOI: 10.15625/0866-7136/15336. Disponível em: https://vjmech.vast.vn/vjmech/article/view/15336. Acesso em: 8 nov. 2025.