Silva, Irene, Sebastião Araújo Neto, e Jorge Kusdra. 2014. “Biological Activity of Soils under Systems of Organic Farming, Agroforestry and Pasture in the Amazon”. Revista Ciência Agronômica 45 (3). https://periodicos.ufc.br/revistacienciaagronomica/article/view/84468.