APA (7th ed.) Citation

Great Britain. Ordnance Survey. (1940). Iceland. Ordnance Survey.

Chicago Style (17th ed.) Citation

Great Britain. Ordnance Survey. Iceland. [Place of publication not identified]: Ordnance Survey, 1940.

MLA (9th ed.) Citation

Great Britain. Ordnance Survey. Iceland. Ordnance Survey, 1940.