Hainil, Sri, et al. “Quantitative Analysis of Caffeine Levels in Local Coffee (Coffea Sp) Powder on Dabo Island With UV-Vis Spectrophotometry”. Borneo Journal of Pharmacy, vol. 2, no. 2, Nov. 2019, pp. 82-86, https://doi.org/10.33084/bjop.v2i2.897.