ZELINSKII, Y.; VYHOVS’KA, I.; STEFANCHUK, M. Shadow’s problem . Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 5, p. 15–20, 2025. DOI: 10.15407/dopovidi2015.05.015. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/14967. Acesso em: 18 apr. 2026.