SAVCHUK, V.; SAVCHUK, M. An extremal problem for the invariant differential operators on a class of Cauchy-type integrals. Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 4, p. 18–23, 2021. DOI: 10.15407/dopovidi2021.04.018. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/2021-4-3. Acesso em: 22 mar. 2025.