Puspita Sari, N., & Abdoellah, S. (2017). Effectiveness of Humic Acid Application on Growth of Coffee Seedings. Pelita Perkebunan (a Coffee and Cocoa Research Journal), 33(3), 188—194. https://doi.org/10.22302/iccri.jur.pelitaperkebunan.v33i3.293