Bako Baon, J., and J. Pudjiono. “Intensity of Ground Cover Crop Arachis Pintoi, Rhizobium Inoculation and Phosphorus Application and Their Effects on Field Growth and Nutrient Status of Cocoa Plants”. Pelita Perkebunan (a Coffee and Cocoa Research Journal), Vol. 22, no. 2, Aug. 2006, doi:10.22302/iccri.jur.pelitaperkebunan.v22i2.33.