APA (7th ed.) Citation

Krulik, S., & reys, R. E. (1980). Problem solving in school mathematics. National Council of Teachers of Mathematics.

Chicago Style (17th ed.) Citation

Krulik, Stephen, and Robert E. reys. Problem Solving in School Mathematics. Reston, Va: National Council of Teachers of Mathematics, 1980.

MLA (9th ed.) Citation

Krulik, Stephen, and Robert E. reys. Problem Solving in School Mathematics. National Council of Teachers of Mathematics, 1980.