KOVALENKO, I. A.; Rоіtberg Ya. A. On Green’s function of a general elliptical boundary value problem with pseudodifferential boundary conditions . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 23, n. 6, p. 772–777, 1971. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8625. Acesso em: 5 dec. 2025.