APA (7e ed.) Bronvermelding

Johnson, K., & Herr, T. (2001). Problem solving strategies: Crossing the river with dogs and other mathematical adventures. Key Curriculum Press.

Chicago (17e ed.) Bronvermelding

Johnson, Ken, en Ted Herr. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. Emeryville, Calif: Key Curriculum Press, 2001.

MLA (9e ed.) Bronvermelding

Johnson, Ken, en Ted Herr. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. Key Curriculum Press, 2001.