3Shuhnan, L. S. Those Who Understand: Knowledge Growth in Teaching[J].Educational Researcher, 1986,15 (2):4-14.
4Shulman, L. S. Knowledge and Teaching: Foundation of New Reform. Harvard[J].Educational Review, 1987,57( 1 ) : 1-22.
5Caldwel,J.H, & Masat.F,E.(1991).A Knapsack Problem, Critical-Path Analysis, and Expression Trees [A].In M.J.Kenney & C.R. Hirsch (eds), Discrete Mathematics Across the Curriculum,K-12, the 1991 Yearbook of the National Council of Teachers of Mathematics[C].Reston, VA:National Council of Teachers of Mathematics.