Rosa, Hamilton Telles, et al. “Thermal Time Methods and Sowing Dates in Phyllochron Determination in Wheat Cultivars”. Pesquisa Agropecuaria Brasileira, vol. 44, no. 11, Dec. 2010, pp. 1347-82, doi:10.1590/S1678-3921.pab2009.v44.2166.