Quintín L., C., J. C. Montoya S., and I. E. Paz N. “Release of CO2 into the Atmosphere by Rhizosphere Activity of Different Crops in the Coffee-Growing Region of the Department of Cauca”. Revista De Ciencias Agrícolas, vol. 32, no. 2, Dec. 2015, pp. 68-76, doi:10.22267/rcia.153202.14.