KALITA, E. A. Partial regularity of traces of solutions of higher-order nonlinear elliptic systems. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 45, n. 11, p. 1495–1502, 1993. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5956. Acesso em: 5 dec. 2025.