Ricci, Marta dos Santos Freire, et al. “Organic Cultivation of Coffee Cultivars Grown under Full Sun and under Shading”. Pesquisa Agropecuaria Brasileira, vol. 41, no. 4, Apr. 2006, pp. 569-75, doi:10.1590/S1678-3921.pab2006.v41.7176.