Reference for “Selectors Level 3”

@TechReport{Hickson:09:SL,
  author      = "Ian Hickson and Tantek \c{C}elik and Daniel Glazman and Elika J. Etemad and John Williams and Peter Linss",
  title       = "Selectors Level 3",
  month       = dec,
  note        = "http://www.w3.org/TR/2009/PR-css3-selectors-20091215",
  year        = "2009",
  bibsource   = "http://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Proposed Reccommendation",
  institution = "W3C",
}