APA (7th ed.) Citation

Gregory, K. J., & Walling, D. E. (1981). Man and environmental processes: A physical geography perspective. Butterworths.

Chicago Style (17th ed.) Citation

Gregory, K. J., and D. E. Walling. Man and Environmental Processes: A Physical Geography Perspective. London: Butterworths, 1981.

MLA (9th ed.) Citation

Gregory, K. J., and D. E. Walling. Man and Environmental Processes: A Physical Geography Perspective. Butterworths, 1981.