Noerhadi, E., T. Yasuda, A. Siregar, and R. G. Budji. “Induction of Somatic Embryos in Cultured Leaf Explants of Coffea Arabica”. Journal of Mathematical and Fundamental Sciences, vol. 18, no. 2/3, Jan. 2019, pp. 41-49, https://journals.itb.ac.id/index.php/jmfs/article/view/9518.