Perez, K.S.S., Ramos, M.L.G. and McManus, C. (2005) “Microbial biomass nitrogen in soil cultivated with soybean, under different management systems, in the Cerrado”, Pesquisa Agropecuaria Brasileira, 40(2), pp. 137–144. doi:10.1590/S1678-3921.pab2005.v40.6934.