NOLS, E. Réflexions en vue d’une ventilation régionale des statistiques. JORBEL - Belgian Journal of Operations Research, Statistics, and Computer Science, [S. l.], v. 7, n. 3-4, p. 45–52, 1967. Disponível em: https://www.orbel.be/jorbel/index.php/jorbel/article/view/189. Acesso em: 4 may. 2024.