1. EPA (United States Environmental Protection Agency). Primer for municipal wastewater treatment systems. Washington DC: EPA; 2004. [accessed 21.09.12]
2. Integrated coastal management project. Wastewater treatment guidance manual. [accessed 21.09.12].
3. Bogner J, Abdelrafie Ahmed M, Diaz C, Faaij A, Gao Q, Hashimoto S, et al. Waste management. In: Metz B, Davidson OR, Bosch PR, Dave R, Meyer LA, editors. Climate change: mitigation. Contribution of working group III to the fourth assessment report of the intergovernmental panel on climate change. New York, Cambridge: Cambridge University Press; 2007. p. 585–618.
4. Comparison of municipal wastewater treatment plants for big centres of population in Galicia (Spain);Hospido;Int J LCA,2007
5. Principles and potential of the anaerobic digestion of waste-activated sludge;Appels;Prog Energy Combust Sci,2008