Assis, Francisco Neto de, and Marta Elene G. Mendez. “Relationship Between Photosyndietically Active Radiation and Global Radiation”. Pesquisa Agropecuaria Brasileira, vol. 24, no. 7, Apr. 2014, pp. 797-00, doi:10.1590/S1678-3921.pab1989.v24.15922.