APA-referens (7:e uppl.)

Verduin, J. R., & Clark, T. A. (1991). Distance education: The foundations of effective practice. Jossey-Bass.

Chicago-referens (17:e uppl.)

Verduin, John R., och Thomas A. Clark. Distance Education: The Foundations of Effective Practice. San Francisco: Jossey-Bass, 1991.

MLA-referens (8:e uppl.)

Verduin, John R., och Thomas A. Clark. Distance Education: The Foundations of Effective Practice. Jossey-Bass, 1991.