EYDELMAN, S. D.; FIRDMAN, A. I. On harmonic functions satisfying nonlocal boundary conditions. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 4, p. 462–467, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5749. Acesso em: 15 dec. 2025.