Maia, Suelen Cristina Mendonça, et al. “Criteria for Topdressing Nitrogen Application to Common Bean Using Chlorophyll Meter”. Pesquisa Agropecuaria Brasileira, vol. 52, no. 7, July 2017, pp. 512-20, doi:10.1590/S1678-3921.pab2017.v52.22334.