Santos, C. A. F., Araújo, F. P. de and Menezes, E. A. (2000) “Yield performance of cowpea genotypes under irrigated and rainfed conditions in Petrolina and Juazeiro, Brazil”, Pesquisa Agropecuaria Brasileira, 35(11), pp. 2229–2234. doi: 10.1590/S1678-3921.pab2000.v35.6016.