Rodrigues, Antonio Carlos da Gama, and Ricardo Augusto Calheiros de Miranda. “Variation of PH and of Nutrients Content of Rainfall and Throughfall in a Southern Bahia Cacao Agrosystem”. Pesquisa Agropecuaria Brasileira, vol. 27, no. 5, May 1992, pp. 771-6, doi:10.1590/S1678-3921.pab1992.v27.3710.