ANOP, A. A. Lawruk elliptic boundaryvalue problems for homogeneous differential equations. Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 2, p. 3–11, 2024. DOI: 10.15407/dopovidi2019.02.003. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/2019-2-1. Acesso em: 18 jun. 2025.