“ Identifying the Factor That Promotes Vertical Partner-Ships: Empirical Evidence from Tier-1 and Tier-2 Compa-Nies in Jabodetabek-Indonesia”. Indonesian Journal of Science and Technology, vol. 4, no. 1, Apr. 2019, pp. 119-33, https://ijost.upi.edu/index.php/ijost/article/view/205.