BABENKO, V. F.; KOVALENKO, O. On interpolational and extremal properties of periodic perfect splines . Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 6, p. 7–11, 2025. DOI: 10.15407/dopovidi2014.12.007. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/17261. Acesso em: 1 may. 2026.