Citazione Stile APA (7a Edizione)

KRASHEN, S. D., & TERRELL, T. D. (1984). The natural approach: Language acquisition in the classroom. Pergamon Press.

Citazione stile Chigago Style (17a edizione)

KRASHEN, Stephen D., e Tracy D. TERRELL. The Natural Approach: Language Acquisition in the Classroom. Oxford: Pergamon Press, 1984.

Citatione MLA (9a ed.)

KRASHEN, Stephen D., e Tracy D. TERRELL. The Natural Approach: Language Acquisition in the Classroom. Pergamon Press, 1984.