Cita APA (7a ed.)

Widdowson, H. (1990). Aspects of language teaching (1st. ed.). Oxford University.

Cita Chicago Style (17a ed.)

Widdowson, H.G. Aspects of Language Teaching. 1st. ed. New York: Oxford University, 1990.

Cita MLA (9a ed.)

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