Silva, E.C. da et al. 2014. The use of a quadratic model to determine the size and shape of plots in experiments with cowpea intercropped with corn. Pesquisa Agropecuaria Brasileira. 19, 10 (Apr. 2014), 1267–1270. DOI:https://doi.org/10.1590/S1678-3921.pab1984.v19.16129.