P. Garzón, V. de L. Ochoa-Herrera, and R. Peñafiel, “Methane gas generation from palm oil mill effluent in experimental biodigesters”, ACI Av. Cienc. Ing. (Quito), vol. 7, no. 2, Dec. 2015, doi: 10.18272/aci.v7i2.274.