Gass, S. M., & Selinker, L. (2008). Second language acquisition: An introductory course (3rd ed.). Routledge/Taylor and Francis Group.

Gass, Susan M., and Larry Selinker. Second Language Acquisition: An Introductory Course. 3rd ed. New York: Routledge/Taylor and Francis Group, 2008.

Gass, Susan M., and Larry Selinker. Second Language Acquisition: An Introductory Course. 3rd ed. Routledge/Taylor and Francis Group, 2008.