Candaş Uygan, Aytaç Kurtuluş. “Effects of Teaching Activities via Google Sketchup and Concrete Models on Spatial Skills of Preservice Mathematics Teachers”. Turkish Journal of Computer and Mathematics Education (TURCOMAT), vol. 7, no. 3, Dec. 2016, pp. 510-35, https://turcomat.org/index.php/turkbilmat/article/view/137.