Johnson, K. (2001). Problem solving strategies: Crossing the river with dogs and other mathematical adventures (2nd ed.). Key Curriculum Press.
Cita Chicago (17th ed.)Johnson, Ken. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. 2nd ed. Emeryville, CA: Key Curriculum Press, 2001.
Cita MLA (9th ed.)Johnson, Ken. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. 2nd ed. Key Curriculum Press, 2001.
Atenció: Aquestes cites poden no estar 100% correctes.