USTYANICH, E. .; USTYANICH, A. . About a practical method of determining the length of an ellipse . Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 9, p. 10–18, 2024. DOI: 10.15407/dopovidi2020.09.010. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/2020-9-2. Acesso em: 18 apr. 2026.