Davidović, Dušan, and Želimir Kešetović. “Comparative Overview of Legislation Governing Private Security in the EU”. Zbornik Instituta Za kriminološka I sociološka istraživanja, vol. 28, no. 1–2, Dec. 2009, pp. 79–92, https://zbornik-iksi.rs/index.php/home/article/view/120.