APA (7th ed.) Citation

Brown, R. (1973). A first language: The early stages (1. publ.). Penguin Books.

Chicago Style (17th ed.) Citation

Brown, Roger. A First Language: The Early Stages. 1. publ. Harmondsworth [u.a.]: Penguin Books, 1973.

MLA (9th ed.) Citation

Brown, Roger. A First Language: The Early Stages. 1. publ. Penguin Books, 1973.