Murach, A.A., and I.S. Chepurukhina. “Elliptic Problems With Nonclassical Coundary Conditions in an Extended Sobolev Scale”. Reports of the National Academy of Sciences of Ukraine, no. 8 (August 28, 2020): 3–10. Accessed June 19, 2026. https://nasu-periodicals.org.ua/index.php/dp/article/view/2020-8-1.