Tilley, E.; Ulrich, L.; Lüthi, C.; Reymond, Ph.; Zurbrügg, C. (2014). Compendium of Sanitation Systems and Technologies – (2nd Revised ed.). Swiss Federal Institute of Aquatic Science and Technology (Eawag), Duebendorf, Switzerland. ISBN 978-3-906484-57-0. Archived from the original on 8 April 2016. 978-3-906484-57-0