Saputri, Maya, et al. “PEMETAAN KARAKTERISTIK KIMIA BIJI KOPI ARABIKA GAYO DAN ROBUSTA GAYO”. Jurnal Teknologi Dan Industri Pangan, vol. 31, no. 1, June 2020, pp. 76-85, https://doi.org/10.6066/jtip.2020.31.1.76.