APA (7th ed.) Citation

Knapp, K., Seidlhofer, B., & Widdowson, H. G. (2009). Handbook of foreign language communication and learning. Mouton de Gruyter.

Chicago Style (17th ed.) Citation

Knapp, Karlfried, Barbara Seidlhofer, and Henry George Widdowson. Handbook of Foreign Language Communication and Learning. New York: Mouton de Gruyter, 2009.

MLA (9th ed.) Citation

Knapp, Karlfried, et al. Handbook of Foreign Language Communication and Learning. Mouton de Gruyter, 2009.