Plesha, M. I. 2001. “Unimprovable Integral Estimate for Solutions of the Dirichlet Problem for Quasilinear Elliptic Equations of the Second Order in a Neighborhood of an Edge”. Ukrains’kyi Matematychnyi Zhurnal 53 (6), 860-65. https://umj.imath.kiev.ua/index.php/umj/article/view/4307.