Kirti Tewari and  Rahul Dev,  Performance Analysis of Modified Solar Water Heating System for Climatic Condition of Allahabad, India.   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2016, vol. 109(1). 73 - 80
    [viewed 18 September 2020]. Available from: https://publications.waset.org/pdf/10003486.