FUCHS, M.; GONGBAO, L.; MARTIO, O. Second order obstacle problems for vectorial functions and integrands with subquadratic growth. Annales Fennici Mathematici, [S. l.], v. 23, n. 2, p. 549–558, 1998. Disponível em: https://afm.journal.fi/article/view/134934. Acesso em: 19 may. 2024.