Koolnapadol, N., S. Tamna, W. Chingtuaythong, S. Skullong, and P. Promvonge. “Experimental investigation on convection heat transfer in solar air heater with perforated-winglet vortex generators”. Engineering and Applied Science Research, vol. 43, Nov. 2016, pp. 287-90, https://ph01.tci-thaijo.org/index.php/easr/article/view/70215.