Prawoto, Adi. 2008. “Coffee Yield and Mineral Cycle in Intercropping of Coffea Canephora and Some Species of Timber Shade Trees”. Pelita Perkebunan (a Coffee and Cocoa Research Journal) 24 (1). https://doi.org/10.22302/iccri.jur.pelitaperkebunan.v24i1.92.