@incollection {accessibility-metrics-report_FPWD,
  author = {W3C WAI Research and Development Working Group (RDWG)},
  title = {Research Report on Web Accessibility Metrics},
  booktitle = {W3C WAI Symposium on Website Accessibility Metrics},
  publisher = {W3C Web Accessibility Initiative (WAI)},
  year = {2012}, month = {August},
  editor = {Markel Vigo and Giorgio Brajnik and Joshue O Connor eds.},
  series = {W3C WAI Research and Development Working Group (RDWG) Notes},
  type = {Research Report},
  edition = {First Public Working Draft},
  url = {http://www.w3.org/TR/accessibility-metrics-report},
}