APA (7th ed.) Citation

Upton, C., & Widdowson, J. D. A. (2006). An atlas of English dialects (2nd ed.). Routledge.

Chicago Style (17th ed.) Citation

Upton, Clive, and J. D. A. Widdowson. An Atlas of English Dialects. 2nd ed. London: Routledge, 2006.

MLA (9th ed.) Citation

Upton, Clive, and J. D. A. Widdowson. An Atlas of English Dialects. 2nd ed. Routledge, 2006.