Reference for “Units in MathML”

@TechReport{Devitt:03:UM,
  author      = "Stan Devitt and Douglas Wilhelm Harder",
  title       = "Units in {MathML}",
  month       = nov,
  note        = "http://www.w3.org/TR/2003/NOTE-mathml-units-20031110/",
  year        = "2003",
  bibsource   = "http://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Note",
  institution = "W3C",
}