DUBOVENKO, Y. I. On the definition of a contact within the Sretenskii model class . Reports of the National Academy of Sciences of Ukraine, Kyiv, Ukraine, n. 3, p. 87–93, 2025. DOI: 10.15407/dopovidi2015.03.087. Disponível em: https://nasu-periodicals.org.ua/index.php/dp/article/view/14127. Acesso em: 13 may. 2025.