DAVIDOVIĆ, Dušan. Toward History of Private Security. Zbornik Instituta za kriminološka i sociološka istraživanja, Belgrade, Serbia, v. 26, n. 1–2, p. 323–337, 2007. Disponível em: https://zbornik-iksi.rs/index.php/home/article/view/93. Acesso em: 4 apr. 2026.