1. [1] Don Vito, P. A., The Essentials of a Planning-Programming-Budgeting System. Santa Monica, CA: RAND Corporation, 1969. Available from:https://www.rand.org/pubs/papers/P4124.html.
2. [2] https://www.bbc.co.uk/bitesize/guides/z342mp3/revision/4.
3. [3] Miriam Valverde, “Border fence in Israel cut illegal immigration by 99 percent”, February 13th, 2017, available from: on https://www.politifact.com/truth-o-meter/statements/2017/feb/13/ron-johnson/border-fence-israel-cut-illegal-immigration-99-per/.
4. [4] Available from: https://docplayer.fr/57391186-Pour-une-vive-memoire.html.
5. [5] Report: “Defeating Insurgency On The Border”, available from: https://www.globalsecurity.org/military/library/report/1985/HJR.htm.