APA (7th ed.) Citation

Great Britain, Great Britain, & Great Britain. (1980). Traffic signs manual ([New ed.].). H.M.S.O.

Chicago Style (17th ed.) Citation

Great Britain, Great Britain, and Great Britain. Traffic Signs Manual. [New ed.]. London: H.M.S.O, 1980.

MLA (9th ed.) Citation

Great Britain, et al. Traffic Signs Manual. [New ed.]. H.M.S.O, 1980.