APA (7th ed.) Citation

Gass, S. M., & Selinker, L. (2001). Second language acquisition: An introductory course (2nd ed.). L. Erlbaum Associates.

Chicago Style (17th ed.) Citation

Gass, Susan M., and Larry Selinker. Second Language Acquisition: An Introductory Course. 2nd ed. Mahwah, N.J: L. Erlbaum Associates, 2001.

MLA (9th ed.) Citation

Gass, Susan M., and Larry Selinker. Second Language Acquisition: An Introductory Course. 2nd ed. L. Erlbaum Associates, 2001.