APA (7th ed.) Citation

Pounds, N. J. G. (1968). The Ruhr: A study in historical and economic geography. Greenwood Press.

Chicago Style (17th ed.) Citation

Pounds, Norman J. G. The Ruhr: A Study in Historical and Economic Geography. New York: Greenwood Press, 1968.

MLA (8th ed.) Citation

Pounds, Norman J. G. The Ruhr: A Study in Historical and Economic Geography. Greenwood Press, 1968.