APA (7th ed.) Citation

Keegan, D. (1993). Theoretical principles of distance education. Routledge.

Chicago Style (17th ed.) Citation

Keegan, Desmond. Theoretical Principles of Distance Education. London: Routledge, 1993.

MLA (9th ed.) Citation

Keegan, Desmond. Theoretical Principles of Distance Education. Routledge, 1993.

Warning: These citations may not always be 100% accurate.