On the spectrum of a boundary problem for the biharmonic equation in the half-space. Neliniini Kolyvannya, [S. l.], v. 3, n. 1, p. 44–48, 2000. Disponível em: https://nosc.imath.kiev.ua/index.php/nosc/article/view/94. Acesso em: 12 apr. 2026.