ŠIMÁK, L. SCIENTIFIC - RESEARCH ACTIVITIES ON SECURITY LEVEL. Perner’s Contacts, [S. l.], v. 5, n. 2, p. 80–86, 2010. Disponível em: https://pernerscontacts.upce.cz/index.php/perner/article/view/982. Acesso em: 5 kvě. 2024.