APA (7th ed.) Citation

Sewart, D., Keegan, D., & Holmberg, B. (1983). Distance education: International perspectives. Croom Helm.

Chicago Style (17th ed.) Citation

Sewart, David, Desmond Keegan, and Borje Holmberg. Distance Education: International Perspectives. London: Croom Helm, 1983.

MLA (9th ed.) Citation

Sewart, David, et al. Distance Education: International Perspectives. Croom Helm, 1983.