APA (7th ed.) Citation

Heatley, D. P. (1919). Diplomacy and the study of international relations. Clarendon Press.

Chicago Style (17th ed.) Citation

Heatley, D. P. Diplomacy and the Study of International Relations. Oxford: Clarendon Press, 1919.

MLA (9th ed.) Citation

Heatley, D. P. Diplomacy and the Study of International Relations. Clarendon Press, 1919.