Al-Qadami, E.H.H. and Ahsan, A. and Abdurrasheed, A.S. and Mustaffa, Z. and Yusof, K.W. and Takaijudin, H. and Malek, M.A. (2019) Yield efficiency evaluation of double slope solar stills connected with external spiral copper for potable water production. Journal of Ecological Engineering, 20 (7). pp. 176-186. ISSN 22998993