Cita APA (7a ed.)

Herr, T., & Johnson, K. (1994). Problem solving strategies: Crossing the river with dogs and other mathematical adventures. Key Curriculum Press.

Cita Chicago Style (17a ed.)

Herr, Ted, y Ken Johnson. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. Berkeley, Calif: Key Curriculum Press, 1994.

Cita MLA (9a ed.)

Herr, Ted, y Ken Johnson. Problem Solving Strategies: Crossing the River with Dogs and Other Mathematical Adventures. Key Curriculum Press, 1994.