Erwiyono, Rudy, Achmad Sucahyo, Suyono ., and Sugeng Winarso. 2006. “Effectiveness of Foliar Application of Potassium on Flowering and Fruiting of Cocoa”. Pelita Perkebunan (a Coffee and Cocoa Research Journal) 22 (1). https://doi.org/10.22302/iccri.jur.pelitaperkebunan.v22i1.26.