APA (7th ed.) Citation
Trudgill, P. (1979). Sociolinguistics: An introduction. Penguin Books.
Chicago Style (17th ed.) Citation
Trudgill, Peter. Sociolinguistics: An Introduction. Nueva York: Penguin Books, 1979.
MLA (9th ed.) Citation
Trudgill, Peter. Sociolinguistics: An Introduction. Penguin Books, 1979.
Warning: These citations may not always be 100% accurate.