Voitovich, M. V., & Kovalevskii, A. A. (2006). 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, 58(11), 1511–1524. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/3551