APA (7th ed.) Citation

Widdowson, H. G. (1990). Aspects of language teaching (1a. ed.). Oxford University Press.

Chicago Style (17th ed.) Citation

Widdowson, H. G. Aspects of Language Teaching. 1a. ed. Oxford: Oxford University Press, 1990.

MLA (9th ed.) Citation

Widdowson, H. G. Aspects of Language Teaching. 1a. ed. Oxford University Press, 1990.