Tuba GÖKÇEK, Mihriban HACISALİHOĞLU KARADENİZ. 2013. “Reasons for Choosing Alternative Sources Instead of Textbook at Secondary Education”. Turkish Journal of Computer and Mathematics Education (TURCOMAT) 4 (1):20-31. https://www.turcomat.org/index.php/turkbilmat/article/view/48.