OSIPCHUK, M. M.; PORTENKO, N. I. On Simple-Layer Potentials for One Class of Pseudodifferential Equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 67, n. 11, p. 1512–1524, 2015. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/2086. Acesso em: 5 dec. 2025.