Johnson, K. (2001). Problem solving strategies: Crossing the river with dogs and other mathematical adventures (2nd ed.). Key Curriculum Press.
Chicago-Zitierstil (17. Ausg.)Johnson, Ken. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. 2nd ed. Emeryville, CA: Key Curriculum Press, 2001.
MLA-Zitierstil (9. Ausg.)Johnson, Ken. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. 2nd ed. Key Curriculum Press, 2001.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.