Citazione Stile APA (7a Edizione)

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

Citazione stile Chigago Style (17a edizione)

Verduin, John R. Jr, e Thomas A. Clark. Distance Education: The Foundations of Effective Practice. San Francisco, California: Jossey-Bass Inc., Publishers, 1991.

Citatione MLA (9a ed.)

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