ЛЕВЧЕНКО, Є. Г.; ПРУС, Р. Б.; РАБЧУН, Д. І. Conditions of saddle point existence in multilevel information security systems. Ukrainian Scientific Journal of Information Security, [S. l.], v. 19, n. 1, p. 70–76, 2013. DOI: 10.18372/2225-5036.19.4707. Disponível em: http://jrnl.kai.edu.ua/index.php/Infosecurity/article/view/4707. Acesso em: 13 jun. 2026.