APA (7th ed.) Citation

(1998). The open ended approach: A new proposal for teaching mathematics (2. printing.). National Council of Teachers of Mathematics.

Chicago Style (17th ed.) Citation

The Open Ended Approach: A New Proposal for Teaching Mathematics. 2. printing. Reston, Va: National Council of Teachers of Mathematics, 1998.

MLA (9th ed.) Citation

The Open Ended Approach: A New Proposal for Teaching Mathematics. 2. printing. National Council of Teachers of Mathematics, 1998.