Gazel Teixeira, P.E., Fernandes, A.R., Galvão, J.R., da Silveira Pereira, W.V., Almeida Casanova, S.R. y da Costa Alves Filho, P.P. 2016. Cowpea yield on soils with residues of NPK and natural phosphate fertilizers in succession the area of degraded pasture. Revista Ceres. 63, 4 (sep. 2016).