Sahide, Muhammad Alif Kaimuddin, et al. “Towards State Hegemony Over Agricultural Certification: From Voluntary Private to Mandatory State Regimes on Palm Oil in Indonesia”. Jurnal Manajemen Hutan Tropika, vol. 21, no. 3, Dec. 2015, pp. 162-71, https://journal.ipb.ac.id/jmht/article/view/10798.