Apriliani, S., Sudradjat, S., & Yahya, S. (2017). Optimization of N, P, and K Single Fertilizer Package for Oil Palm Aged Four Years. International Journal of Sciences: Basic and Applied Research (IJSBAR), 36(1), 202–212. Retrieved from https://www.gssrr.org/index.php/JournalOfBasicAndApplied/article/view/7973