Cita APA (7a ed.)

Willis, B. (1993). Distance education: A practical guide. Educational Technology Publications.

Cita Chicago Style (17a ed.)

Willis, Barry. Distance Education: A Practical Guide. Englewood Cliffs, N.J.: Educational Technology Publications, 1993.

Cita MLA (9a ed.)

Willis, Barry. Distance Education: A Practical Guide. Educational Technology Publications, 1993.