Reference for “XHTML Role Attribute Module”

@TechReport{Schwerdtfeger:08:XRA,
  author      = "Richard Schwerdtfeger and Steven Pemberton and Shane McCarron and T. V. Raman and Mark Birbeck",
  title       = "{XHTML} Role Attribute Module",
  month       = apr,
  note        = "http://www.w3.org/TR/2008/WD-xhtml-role-20080407",
  year        = "2008",
  bibsource   = "http://w2.syronex.com/jmr/w3c-biblio",
  type        = "Last Call {WD}",
  institution = "W3C",
}