Anop, A.V., and A.A. Murach. “Homogeneous Elliptic Equations in an Extended Sobolev Scale”. Reports of the National Academy of Sciences of Ukraine, no. 3 (March 28, 2018): 3–11. Accessed June 20, 2026. https://nasu-periodicals.org.ua/index.php/dp/article/view/2566.