M. Andry, F. Shufyani, M. A. Nasution, M. F. Fadillah, I. J. Tambunan, and F. Rezaldi, “Phytochemical Screening and Analysis of Caffeine Content in Arabica Ground Coffee in Takengon City Using Spectrophotometry Ultraviolet”, JPS, vol. 6, no. 3, pp. 998–1006, Jul. 2023.