APA (7th ed.) Citation

Trudgill, P. (1974). Sociolinguistics: An introduction. Penguin.

Chicago Style (17th ed.) Citation

Trudgill, Peter. Sociolinguistics: An Introduction. Harmondsworth, Middlesex: Penguin, 1974.

MLA (9th ed.) Citation

Trudgill, Peter. Sociolinguistics: An Introduction. Penguin, 1974.