Putong, Iskandar. “Faktor Permintaan Non Fungsional Group Member Terhadap Permintaan (Seri 1)”. Binus Business Review 1, no. 2 (November 30, 2010): 351–362. Accessed January 24, 2026. https://journal.binus.ac.id/index.php/bbr/article/view/1081.