Citazione Stile APA (7a Edizione)

Krashen, S. D. (1985). The input hypothesis: Issues and implications. Longman.

Citazione stile Chigago Style (17a edizione)

Krashen, Stephen D. The Input Hypothesis: Issues and Implications. London ; New York: Longman, 1985.

Citatione MLA (8a ed.)

Krashen, Stephen D. The Input Hypothesis: Issues and Implications. Longman, 1985.