1. Online nation: Five years of growth in online learning;Allen,2007
2. Student perceptions of their distance education courses (report no. BSU-RR-2001-04);Belcheir,2001
3. Registrations in WebCT class sections by modality;Center for Distributed Learning University of Central Florida,2007
4. Communication barriers in distance education: “Text-based internet-enabled courses.”;Dabaj;International Journal of Instructional Technology and Distance Learning,2004
5. Student involvement in online learning;Dziuban,2007