Chepurukhina, I.S., and A.A. Murach. 2021. “Elliptic Problems in Besov and Sobolev—Triebel—Lizorkin Spaces of Low Regularity”. Reports of the National Academy of Sciences of Ukraine, no. 6 (December). Kyiv, Ukraine:3-11. https://doi.org/10.15407/dopovidi2021.06.003.