informational resources list on measuring web accessibility?

Hi, I was wondering if we did a literature survey to determine the current state of the practice of web accessibility measurement.   If we did I apologize for having forgotten.   I remember for the WAI Ageing Task Force, they did a literature survey at the beginning to leverage existing resources.  Perhaps in our document we could have a informative resources list for further reading at the end if appropriate..  Some examples (no endorsement implied, just informational) I found of some resources on measuring web accessibility were:

Remaining Challenges of Measuring the Accessibility of Websites According to WCAG2.0:
http://egovernments.wordpress.com/2010/08/11/remaining-challenges-of-measuring-the-accessibility-of-web-sites-according-to-wcag-2-0/

Quantitative Metrics for Measuring Web Accessibility (link to paper in PDF):
http://dl.acm.org/citation.cfm?id=1243465

Delivering Inclusive Websites-Measuring Accessibility:
http://coi.gov.uk/guidance.php?page=134

Automatic Testing, Page Sampling, and Measuring Web Accessibility:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.143.9881&rep=rep1&type=pdf.

Thanks and best wishes
Tim Boland NIST