Nogueira, O.L. et al. 2014. Micronutrients deficiencies and aluminum and manganese toxicity in cowpea - II - plant growth and chemical composition. Pesquisa Agropecuaria Brasileira. 17, 5 (Apr. 2014), 663–669. DOI:https://doi.org/10.1590/S1678-3921.pab1982.v17.15847.