1. Anderson, J.R., Corbett, A.T., Koedinger, K.R., Pelletier, R.: Cognitive tutors: Lessons learned. The Journal of the Learning Sciences 4(2), 167–207 (1995)
2. Anderson, J.R., Reiser, B.J.: The lisp tutor. Byte 10(4), 159–175 (1985)
3. Blischke, W.R., Murthy, D.P.: Reliability: Modeling, prediction, and optimization, vol. 767. Wiley (2011)
4. Breen, R., Lindsay, R., Jenkins, A., Smith, P.: The role of information and communication technologies in a university learning environment. Studies in Higher Education 26(1), 95–114 (2001)
5. Crow, E.L., Shimizu, K.: Lognormal distributions: Theory and applications, vol. 88. CRC Press, LLC (1988)