MEL'NIK, Yu. I.; PODLIPENKO, Yu. K. On Green’s function for the Helmholtz equation in a wedge. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 9, p. 1312–1314, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5935. Acesso em: 5 dec. 2025.