Citazione Stile APA (7a Edizione)

Helm, J. H., & Katz, L. G. (2011). Young investigators: The project approach in the early years (2nd ed.). Teachers College Press.

Citazione stile Chigago Style (17a edizione)

Helm, Judy Harris, e Lilian G. Katz. Young Investigators: The Project Approach in the Early Years. 2nd ed. New York: Teachers College Press, 2011.

Citatione MLA (9a ed.)

Helm, Judy Harris, e Lilian G. Katz. Young Investigators: The Project Approach in the Early Years. 2nd ed. Teachers College Press, 2011.