APA (7e ed.) Bronvermelding

Johnson, K. (2001). Problem solving strategies: Crossing the river with dogs and other mathematical adventures (2nd ed.). Key Curriculum Press.

Chicago (17e ed.) Bronvermelding

Johnson, Ken. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. 2nd ed. Emeryville, CA: Key Curriculum Press, 2001.

MLA (9e ed.) Bronvermelding

Johnson, Ken. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. 2nd ed. Key Curriculum Press, 2001.