1. Bloom B. S. (1969). Taxonomy of Educational Objectives: The Classification of Educational Goals Handbook I: Cognitive Domain. United Kingdom Longman Group. Bloom B. S. (1969). Taxonomy of Educational Objectives: The Classification of Educational Goals Handbook I: Cognitive Domain. United Kingdom Longman Group.
2. Lord F. M. (1980). Applications of Item Response Theory to Practical Testing Problems. Hillsdale New Jersey Lawrence Erlbaum Associates. Lord F. M. (1980). Applications of Item Response Theory to Practical Testing Problems. Hillsdale New Jersey Lawrence Erlbaum Associates.
3. Webley K. (2012). "MOOC Brigade: Who Is Taking Massive Open Online Courses And Why?". from http://nation.time.com/2012/09/26/mooc-brigade-who-is-taking-massive-open-online-courses-and-why/. Webley K. (2012). "MOOC Brigade: Who Is Taking Massive Open Online Courses And Why?". from http://nation.time.com/2012/09/26/mooc-brigade-who-is-taking-massive-open-online-courses-and-why/.
4. What do students know?