Citazione Stile APA (7a Edizione)

Opitz, M. F. (1994). Learning centers: Getting them started, keeping them going. Scholastic Professional Books.

Citazione stile Chigago Style (17a edizione)

Opitz, Michael F. Learning Centers: Getting Them Started, Keeping Them Going. New York: Scholastic Professional Books, 1994.

Citatione MLA (9a ed.)

Opitz, Michael F. Learning Centers: Getting Them Started, Keeping Them Going. Scholastic Professional Books, 1994.