APA (7th ed.) Citation

Upton, C., & Widdowson, J. D. A. (2006). An Atlas of English dialects. Routledge.

Chicago Style (17th ed.) Citation

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

MLA (8th ed.) Citation

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

Warning: These citations may not always be 100% accurate.