KENGNE, E. Well-Posed and Regular Nonlocal Boundary-Value Problems for Partial Differential Equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 8, p. 1135–1142, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4152. Acesso em: 6 dec. 2025.