“Determination of Caffeine Levels from Robusta Coffee Leaf Extract (Coffea Canephora Pierre Ex A. Froehner) and Arabica Coffee Leave (Coffea Arabica L.) With High-Performance Liquid Chromatography Method”. 2023. Journal of Pharmaceutical and Sciences 6 (4): 1544-52. https://doi.org/10.36490/journal-jps.com.v6i4.257.