SAMBASIVA RAO, P. On Eigenfunctions of the Membrane Problem. The Journal of the Indian Mathematical Society, [S. l.], v. 17, n. 1, p. 1–20, 1953. DOI: 10.18311/jims/1953/17024. Disponível em: https://informaticsjournals.com/index.php/jims/article/view/17024. Acesso em: 6 may. 2024.