Setyawan, B., I. Anita-Sari, F. Ihsan, and H. Panua. “Branching Angles of Several Cocoa Genotypes and Their Effect on Determining Optimum Plant Spacing”. Pelita Perkebunan (a Coffee and Cocoa Research Journal), Vol. 37, no. 3, Dec. 2021, pp. 177-83, doi:10.22302/iccri.jur.pelitaperkebunan.v37i3.473.