Cita APA (7th ed.)

Krashen, S. D. (1987). Principles and practice in second language acquisition. Prentice Hall International.

Cita Chicago (17th ed.)

Krashen, Stephen D. Principles and Practice in Second Language Acquisition. Nueva York: Prentice Hall International, 1987.

Cita MLA (9th ed.)

Krashen, Stephen D. Principles and Practice in Second Language Acquisition. Prentice Hall International, 1987.