APA (7th ed.) Citation

Clark, G., Forbes, D., & Johns, G. (1975). On the concept of welfare. Institute of British Geographers.

Chicago Style (17th ed.) Citation

Clark, G., D. Forbes, and G. Johns. On the Concept of Welfare. Institute of British Geographers, 1975.

MLA (9th ed.) Citation

Clark, G., et al. On the Concept of Welfare. Institute of British Geographers, 1975.