1. Potts, J., Lynch, M., Wilkings, A., Huppe, G., Cunningham, M., Voora, V. London: International Institute for Sustainable Development, 2014.
2. Pusat Penelitian Kopi dan Kakao Indonesia. Kopi (Sejarah, Botani, Proses Produksi, Pengolahan, Produk Hilir, dan Sistem Kemitraan). Yogyakarta: Gadjah Mada University Press, 2016.
3. Towaha, J., Rubiyo. J. TIDP, 3(2), 61–70, 2016.
4. Usman, D., Suprihadi, A., Kusdiyantini, E. Jurnal Biologi, Vol 4 No 3, 2015.
5. Farah, A., and Donangelo, C.M. J. Plant Physiol, 18(1):23–36, 2006.