Cochrane, Thomas T., and Djalma M. G. de Sousa. 2014. “A Field Test for Ferrous Iron and Ferric-Organic Complexes in Cerrados Soils”. Pesquisa Agropecuaria Brasileira 21 (3): 327-30. https://doi.org/10.1590/S1678-3921.pab1986.v21.14753.