de Queiroz, Emilson França, et al. “A Mathematical Model for Predicting Dates of Occurrence of Phenologic Stages of Three Soybean Cultivars”. Pesquisa Agropecuaria Brasileira, vol. 31, no. 8, Aug. 1996, pp. 533-42, doi:10.1590/S1678-3921.pab1996.v31.4516.