Bayer, Cimélio, et al. “Carbon Storage in Labile Fractions of Soil Organic Matter in a Tropical No-Tillage Oxisol”. Pesquisa Agropecuaria Brasileira, vol. 39, no. 7, July 2004, pp. 677-83, doi:10.1590/S1678-3921.pab2004.v39.6825.