APA (7th ed.) Citation

Ritter, H. (1986). Dictionary of concepts in history. Greenwood Press.

Chicago Style (17th ed.) Citation

Ritter, Harry. Dictionary of Concepts in History. New York ; Westport, Connecticut ; London: Greenwood Press, 1986.

MLA (9th ed.) Citation

Ritter, Harry. Dictionary of Concepts in History. Greenwood Press, 1986.