APA (7th ed.) Citation

Kortmann, B., & Burridge, K. (2008). Varieties of English. Mouton de Gruyter.

Chicago Style (17th ed.) Citation

Kortmann, Bernd, and Kate Burridge. Varieties of English. Berlin [etc.]: Mouton de Gruyter, 2008.

MLA (9th ed.) Citation

Kortmann, Bernd, and Kate Burridge. Varieties of English. Mouton de Gruyter, 2008.

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