[1]
W. L. Nicomedes, K.-J. Bathe, F. J. S. Moreira and R. C. Mesquita, The method of finite spheres in acoustic wave propagation through nonhomogeneous media: Inf-sup stability conditions, Vietnam J. Mech. 42 (2020) 209–237. DOI: https://doi.org/10.15625/0866-7136/15336.