Arunkumar, T., R. Jayaprakash, and Amimul Ahsan. 2014. “A comparative experimental testing in enhancement of the efficiency of pyramid solar still and hemispherical solar still”. Journal of Renewable Energy and Smart Grid Technology 7 (2):1-8. https://ph01.tci-thaijo.org/index.php/RAST/article/view/26223.