Salles, P.A.A. de and Gonçalves, J.O.N. 2014. Economic efficiency of nitrogen in cultivated pastures. Pesquisa Agropecuaria Brasileira. 16, 1 (Apr. 2014), 27–31. DOI:https://doi.org/10.1590/S1678-3921.pab1981.v16.16464.