Avadhesh Yadav and  V.K. Bajpai,  An Experimental Study on Evacuated Tube Solar Collector for Heating of Air in India.   journal   = {International Journal of Mechanical and Mechatronics Engineering}, [online]. World Academy of Science, Engineering and Technology.
    July 2011, vol. 55(7). 1188 - 1193
    [viewed 17 January 2020]. Available from: https://publications.waset.org/pdf/14741.