Subrata Hait and  Debabrata Mazumder,  High-rate Wastewater Treatment by a Shaft-type Activated Sludge Reactor.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2011, vol. 49(1). 1 - 6
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/14319.