APA (7th ed.) Citation

Watcyn-Jones, P., & Nordqvist, S. (1996). Start testing your vocabulary. Penguin Books.

Chicago Style (17th ed.) Citation

Watcyn-Jones, Peter, and Sven Nordqvist. Start Testing Your Vocabulary. London: Penguin Books, 1996.

MLA (9th ed.) Citation

Watcyn-Jones, Peter, and Sven Nordqvist. Start Testing Your Vocabulary. Penguin Books, 1996.