WASET
    U. Bawa,  Gammarus:Asellus Ratio as an Index of Organic Pollution – (A Case Study in Markeaton, Kedleston Hall, and Allestree Park Lakes Derby) UK.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2015, vol. 99(3). 256 - 265
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/10000656.