D. Hasni, M. Muzaifa, H. P. Widayat, N. Ariska, .-. Maulidar, and D. Rahmad, “Physiochemical Properties and Cupping Quality of Gayo Espresso Coffee Based on Blending Ratio and Roasting Techniques”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 13, no. 4, pp. 1378–1386, Aug. 2023.