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9Blumenfeld,P.C., Soloway, E., Marx,R. W., Krajcik,J.S., Guzdial, M.,& Palincsar, A.(1991). Motivating project-based learning: Sustaining the doing, supporting the learning. Educational Psychologist, 26(3-4), 369-389
10Fischer, F., C., & Mandl,H.(2000). Fostering problem-oriented learning with auxiliary hypertext and graphical information. Paper presened at the Annual Meeting of the American Educational Research Association, New Orleans, LA.(April 24-28,2000)(ERIC Document Reproduction Service No. ED 444 988)