The current edition of  Educational Technology Review (and online journal) is
a special issue: "Accessibility...An Integral Part of Online Learning."  

http://www.aace.org/pubs/etr/current.cfm

Contents:

Editorial: Accessibility...An Integral Part of Online Learning
Deanie French
http://www.aace.org/pubs/etr/french-ed.cfm

Electronic Accessibility: United States and International Perspectives
Deanie French and Leo Valdes
http://www.aace.org/pubs/etr/french-a.cfm

The Need for Assistive Technology in Educational Technology
Terence Cavanaugh
http://www.aace.org/pubs/etr/cavanaugh.cfm

Distance Learning: Universal Design, Universal Access
Sheryl Burgstahler
http://www.aace.org/pubs/etr/burgstahler.cfm

Web Design for Accessibility: Policies and Practice
Alan Foley and Bob Regan
http://www.aace.org/pubs/etr/foley.cfm

Online Course Accessibility: A Call for Responsibility and Necessity
Christine Opitz
http://www.aace.org/pubs/etr/optiz-x1.cfm

