APA (7th ed.) Citation

Frei, B., & Head, H. (1989). The Guinness Book of Answers: The complete reference handbook. Guinness Publishing Ltd.

Chicago Style (17th ed.) Citation

Frei, Beatrice, and Honor Head. The Guinness Book of Answers: The Complete Reference Handbook. London: Guinness Publishing Ltd, 1989.

MLA (9th ed.) Citation

Frei, Beatrice, and Honor Head. The Guinness Book of Answers: The Complete Reference Handbook. Guinness Publishing Ltd, 1989.