VOITOVICH, M. V.; KOVALEVSKII, A. A. On the improvement of summability of generalized solutions of the Dirichlet problem for nonlinear equations of the fourth order with strengthened ellipticity. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 58, n. 11, p. 1511–1524, 2006. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3551. Acesso em: 6 dec. 2025.