F. B. Neto and R. H. Robichaux, “Spatial arrangement and density effects on an annual cotton/cowpea/maize intercrop. II. Yield and biomass”, PAB, vol. 32, no. 10, pp. 1029–1037, Oct. 1997, doi: 10.1590/S1678-3921.pab1997.v32.4752.