Breny, H. “l’Initiation a La Statistique Au Niveau Secondaire”. JORBEL - Belgian Journal of Operations Research, Statistics, and Computer Science 11, no. 4 (March 1, 1972): 13–17. Accessed May 18, 2024. https://www.orbel.be/jorbel/index.php/jorbel/article/view/149.