Chepurukhina, I. S., and A. A. Murach. “Elliptic Boundary-Value Problems in the Sense of Lawruk on Sobolev and Hörmander Spaces”. Ukrains’kyi Matematychnyi Zhurnal 67, no. 5 (May 25, 2015): 672–691. Accessed March 29, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2014.