Sianipar, Corinthias Pamatang Morgana, Kiyoshi Dowaki, Gatot Yudoko, and Akbar Adhiutama. “Seven Pillars of Survivability: Appropriate Technology With a Human Face”. European Journal of Sustainable Development 2, no. 4 (April 1, 2013): 1. Accessed March 29, 2024. http://ecsdev.org/ojs/index.php/ejsd/article/view/76.