APA (7th ed.) Citation

Clark & Sheffield. (2001). World War I: An illustrated history. Helicon Publishing Limited.

Chicago Style (17th ed.) Citation

Clark and Sheffield. World War I: An Illustrated History. Oxford: Helicon Publishing Limited, 2001.

MLA (9th ed.) Citation

Clark and Sheffield. World War I: An Illustrated History. Helicon Publishing Limited, 2001.

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