2010. Pengaruh Pupuk Organik dan Intensitas Naungan terhadap Pertumbuhan Bibit Kopi Robusta (Coffee canephora Pierre ex Froehner). Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy). 30, 1 (Jul. 2010). DOI:https://doi.org/10.24831/jai.v30i1.1422.