Untarawati, Dewik, and Yuda Benharry Tangkulisan. “Civil Aviation in the Netherlands East Indies During the Great Depression, 1928-1934”. International Journal of Engineering & Technology 7, no. 4.28 (November 30, 2018): 115–120. Accessed May 1, 2024. https://www.sciencepubco.com/index.php/ijet/article/view/22563.