Barman P.J and  Kartha S A and  Gupta S and  Pradhan B.,  A Study on Leaching Behavior of Na, Ca and K Using Column Leach Test.   journal   = {International Journal of Environmental and Ecological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    October 2012, vol. 70(10). 679 - 683
    [viewed 26 October 2021]. Available from: https://publications.waset.org/pdf/5439.