“Kajian Lama Fermentasi Terhadap Kadar Kafein, Etanol Dan PH Bubuk Kopi Robusta (Coffea Canephora) Argopuro”. Journal of Food Engineering 2, no. 1 (January 31, 2023): 34–44. Accessed November 8, 2026. https://publikasi.polije.ac.id/jofe/article/view/3743.