Trafton, P. R. (1989). New directions for elementary school mathematics. National Council of Teachers of Mathematics.
Chicagoスタイル(17版)引用形式Trafton, Paul R. New Directions for Elementary School Mathematics. Reston, Va.: National Council of Teachers of Mathematics, 1989.
MLA(8版)引用形式Trafton, Paul R. New Directions for Elementary School Mathematics. National Council of Teachers of Mathematics, 1989.
警告: この引用は必ずしも正確ではありません.