1. Abacus Associates.2000. A survey of traditional and distance learning higher education members (National Education Association). Available online at http://www.nea.org/he/abouthe/d/study.pdf
2. Abe, Y.1988. Communications technology. In World Conference of the International Council for Distance Education: Developing distance education, ed. D. Sewart and J. S. Daniel, 9-15. Varnamo, Sweden: Falths Tryckeri.
3. Work-load and the quality of student learning
4. Is distance teaching more work or less work?