Water and Environmental Health at London and Loughborough (1999). "Waste water Treatment Options."Arhivirano 2011-07-17 na Wayback Machine. Technical brief no. 64. London School of Hygiene & Tropical Medicine and Loughborough University.
Water and Environmental Health at London and Loughborough (1999). "Waste water Treatment Options."Arhivirano 2011-07-17 na Wayback Machine. Technical brief no. 64. London School of Hygiene & Tropical Medicine and Loughborough University.