Yuwita, Fitri, et al. “Prediction of Caffeine and Protein of Arabica Coffee Beans Using Near Infrared Spectroscopy (NIRS)”. Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering), vol. 12, no. 4, Dec. 2023, pp. 852-6, doi:10.23960/jtep-l.v12i4.852-862.