ORIDOROGA, L. L. Boundary value problems for 2x2 Dirac type systems with spectral parameter in boundary conditions. Methods of Functional Analysis and Topology, [S. l.], v. 7, n. 1, p. 82–87, 2001. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/142. Acesso em: 17 dec. 2025.