APA (7th ed.) Citation

Great Britain. MI6. (1944). Zones of France: 1:2,000,000 (Second edition.). [publisher not identified].

Chicago Style (17th ed.) Citation

Great Britain. MI6. Zones of France: 1:2,000,000. Second edition. [England?]: [publisher not identified], 1944.

MLA (9th ed.) Citation

Great Britain. MI6. Zones of France: 1:2,000,000. Second edition. [publisher not identified], 1944.

Warning: These citations may not always be 100% accurate.