ALDASHEV, S. A. Eigenvalues and eigenfunctions of the Gellerstedt problem for the multidimensional Lavrent?ev?Bitsadze equation. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 63, n. 6, p. 827–832, 2011. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2765. Acesso em: 5 dec. 2025.