CHLEBICKA, Iwona; KARPPINEN, Arttu; LI, Ying. A direct proof of existence of weak solutions to elliptic problems. Topological Methods in Nonlinear Analysis, [S. l.], v. 62, n. 2, p. 643–665, 2023. DOI: 10.12775/TMNA.2023.019. Disponível em: https://apcz.umk.pl/TMNA/article/view/47718. Acesso em: 28 jun. 2025.