Asymptotic approximation for the solution to a boundary-value problem with varying type of boundary conditions in a thick two-level junction. Neliniini Kolyvannya, [S. l.], v. 9, n. 3, p. 336–355, 2006. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/401. Acesso em: 21 jan. 2026.