Sukmawan, Yan, ,Sudradjat, and ,Sugiyanta. 2016. “Peranan Pupuk Organik Dan NPK Majemuk Terhadap Pertumbuhan Kelapa Sawit TBM 1 Di Lahan Marginal”. Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) 43 (3), 242-49. https://doi.org/10.24831/jai.v43i3.11251.