DRACH, K. About the isoperimetric property of λ-convex lunes on the Lobachevsky plane . Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 11, p. 11–15, 2025. DOI: 10.15407/dopovidi2014.11.011. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/16813. Acesso em: 10 may. 2026.