1. Méndez A. Obtención de biocombustibles por tratamiento térmico de lodos de depuradora. In: Congreso Europeo de Energías Renovables y Eficiencia Energética. Ávila, Spain; 2005.
2. Principles and potential of the anaerobic digestion of waste-activated sludge;Appels;Progress in Energy and Combustion Science,2008
3. European Environment Agency. Climate change and a European low-carbon energy system. Report 1/2005. EEA (European Environment Agency) and OPOCE (Office for Official Publications of the European Communities); 2005.
4. Metcalf and Eddy, Inc. Wastewater engineering: treatment and reuse. New York: McGraw-Hill; 2003.
5. IEA Bioenergy Task 24: energy from biological conversion of organic waste. Biogas upgrading and utilisation. International Energy Agency; 2000.