APA (7th ed.) Citation

Warn, C. (1980). The Ordnance survey map skills book. Arnold-Wheaton [u.a.

Chicago Style (17th ed.) Citation

Warn, Chris. The Ordnance Survey Map Skills Book. [Leeds]: Arnold-Wheaton [u.a, 1980.

MLA (9th ed.) Citation

Warn, Chris. The Ordnance Survey Map Skills Book. Arnold-Wheaton [u.a, 1980.