APA (7th ed.) Citation

Headlam, J. W. (1930). Studies in diplomatic history. Methuen.

Chicago Style (17th ed.) Citation

Headlam, James Wycliffe. Studies in Diplomatic History. London: Methuen, 1930.

MLA (9th ed.) Citation

Headlam, James Wycliffe. Studies in Diplomatic History. Methuen, 1930.