Ritzhaupt, Albert Dieter, Michelle Stewart, Patryce Smith, and Ann E. Barron. “An Investigation of Distance Education in North American Research Literature Using Co-Word Analysis”. The International Review of Research in Open and Distributed Learning 11, no. 1 (March 5, 2010): 37–60. Accessed May 4, 2024. https://www.irrodl.org/index.php/irrodl/article/view/763.