“Ammonia Volatilization in Cocoa Farm As Affected by Sugarcane Filter Cake Supply at Different Urea and Soil Moisture Levels”. 2015. Pelita Perkebunan (a Coffee and Cocoa Research Journal) 30 (3): 208-19. https://doi.org/10.22302/iccri.jur.pelitaperkebunan.v30i3.63.