BibTeX Reference for “XPath and XQuery Functions and Operators 3.1”

@TechReport{Kay:17:XXF,
  author      = "Michael Kay",
  title       = "{XPath} and {XQuery} Functions and Operators {3.1}",
  month       = mar,
  note        = "https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/",
  year        = "2017",
  bibsource   = "https://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Recommendation",
  institution = "W3C",
}