LUYEN, Duong Trong; TRANG, Mai Thi Thu. Multiple solutions to boundary-value problems for fourth-order elliptic equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 75, n. 6, p. 830–841, 2023. DOI: 10.37863/umzh.v75i6.6958. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/6958. Acesso em: 8 dec. 2025.