1. Chi, M.T.H., Siler, S.A., Jeong, H., Yamauchi, T., Hausmann, R.G.: Learning from Human Tutoring. Cognitive Science. 25(4), 471–533 (2001)
2. VanLehn, K.: The Relative Effectiveness of Human Tutoring, Intelligent Tutoring Systems, and Other Tutoring Systems. Educational Psychologist 46(4), 197–221 (2011)
3. Evans, M., Michael, J.: One-on-one Tutoring by Humans and Computers. Lawrence Erlbaum Associates (2006)
4. Graesser, A.C., Franceschetti, D.R., Gholson, B., Craig, S.D.: Learning Newtonian physics with conversational agents and interactive simulation. In: Stein, N.L., Raudenbush, S. (eds.) Developmental Cognitive Science goes to School, pp. 157–172. Routledge, New York (2011)
5. Zakharov, K., Mitrovic, A., Ohlsson, S.: Feedback micro-engineering in EER-Tutor. In: Proc. 12th Int. Conf. Artificial Intelligence in Education, pp. 718–725 (2005)