3Merrill, D. C., Reiser, B. J., Beekelaar, R., & Hamid, A. Making process visible: scaffolding learning with reasoning-congruent representations [A]. In C. Frasson, G. Gauthier, and I. McCalla (eds.).
4Bloom, B. S. Taxonomy of educational objectives: The classification of educational goals [A]. In B. S. Bloom (Ed.). Cognitive domain, handbook 1 [C]. New York: McKay, 1956. 201--207.
5Crowder, N. A. Automatic tutoring by means of intrinsic programming [A]. In E. Galanter (Ed.).Automatic teaching: The state of the art [C]. New York: John Wiley & Sons, 1959. 106--116.
6Glaser, R. The processes of intelligence and education [A]. In L. B. Resnick (Ed.). The nature of intelligence [C]. Hillsdale, NJ: Erlbaum, 1976. 341--352.
8Burton, R. R. & Brown, J. S. An investigation of computer coaching for informal learning activities. [A]. In D. Sleeman & J. S. Brown (Eds.). Intelligent tutoring systems [C] .London: Academic Press, 1982.
9Lewis, M. W., McArthur, D., Stasz, C., & Zmuidzinas, M. Discovery-based tutoring in mathematics. AAAI Spring Symposium Series [M]. Stanford, CA: Stanford University, 1990.
10Sleeman, D. H. & Brown, J. S. Intelligent tutoring systems [M]. London: Academic Press, 1982.
