Citazione Stile APA (7a Edizione)

Herr, T., & Johnson, K. (1994). Problem solving strategies: Teacher's resource book and answer key. Key Curriculum Press.

Citazione stile Chigago Style (17a edizione)

Herr, Ted, e Ken Johnson. Problem Solving Strategies: Teacher's Resource Book and Answer Key. Berkeley, Calif: Key Curriculum Press, 1994.

Citatione MLA (9a ed.)

Herr, Ted, e Ken Johnson. Problem Solving Strategies: Teacher's Resource Book and Answer Key. Key Curriculum Press, 1994.