APA (7th ed.) Citation

Holmes, A., & Graef, R. (1981). Central London bus map: Going places. London Transport.

Chicago Style (17th ed.) Citation

Holmes, Andrew, and Roger Graef. Central London Bus Map: Going Places. [London]: London Transport, 1981.

MLA (9th ed.) Citation

Holmes, Andrew, and Roger Graef. Central London Bus Map: Going Places. London Transport, 1981.