Putri, Y. N.; Nasution, M. A. .; Ridwanto, R.; Daulay, A. S. Determination of Total Phenolic Content of Ethanol Extract, Ethyl Acetate and N-Hexan Fraction of Robusta Coffee Leaves (Coffea Canephora Pierre Ex A. Froehner) Using Uv-Vis Spectrofotometry Method. JPS 2023, 6, 1709-1716.