Accessibilty reports based on user testing

I now know of three papers on Web accessibility based prominently on 
actual user testing with people with disabilities:

DRC-GB:
<http://www.drc-gb.org/publicationsandreports/report.asp>

BBC:
<http://www.bbc.co.uk/commissioning/bbci/pdf/BBCi_Accessibility_Study_7-10-02.pdf>
(Google the URL for HTML)
<http://www.joeclark.org/axxlog/2003/2003a.html#bbci>

Nielsen Norman Group:
<http://www.nngroup.com/reports/accessibility/> (for a mere US$190 and up)

Are there others?
-- 

     Joe Clark | joeclark@joeclark.org
     Accessibility <http://joeclark.org/access/>
     Expect criticism if you top-post