Pereira, Wander Douglas, et al. “Changes in the Stocks of C and N in Organic Matter Fractions in Soil Cropped With Coffee and Fertilized With Sunn Hemp and Ammonium Sulfate”. Semina: Ciências Agrárias, vol. 39, no. 3, May 2018, pp. 999-1014, doi:10.5433/1679-0359.2018v39n3p999.