Cita APA (7a ed.)

Dulay, H., Krashen, S., & Marina, B. (1981). Language two. s.e..

Cita Chicago Style (17a ed.)

Dulay, Heidi, Stephen Krashen, y Burt Marina. Language Two. San Francisco: s.e., 1981.

Cita MLA (8a ed.)

Dulay, Heidi, et al. Language Two. s.e., 1981.