Sousa, L.B., Stamford, N.P., Oliveira, W.S., Silva, E.V., Santos, C.E. and Stamford, T. 2017. Optimization of Biofertilizers Enriched in N by Diazotrophic Bacteria. European Journal of Sustainable Development. 6, 3 (Oct. 2017), 448. DOI:https://doi.org/10.14207/ejsd.2017.v6n3p448.