1. P21.org. (n.d.). Critical thinking and problem solving. Partnership for 21st Century Skills. Retrieved from http://www.p21.org/index.php?option=com_content&task=view&id=260&Itemid=120
2. Class Acts: Outstanding College Teachers and the Difference they Make
3. Approaches to assessing academic achievement;D. A.Archbald;Toward a new science of educational testing and assessment,1992
4. Birgin, O. (2003). Investigation of the application level of a computer based portfolios. (Unpublished Master’s Thesis). Karadeniz Technical University, Trabzon.