Reference for “SPARQL Query Language for RDF”

@TechReport{Prud'hommeaux:08:SQL,
  author      = "Eric Prud'hommeaux and Andy Seaborne",
  title       = "{SPARQL} Query Language for {RDF}",
  month       = jan,
  note        = "http://www.w3.org/TR/2008/REC-rdf-sparql-query-20080115/",
  year        = "2008",
  bibsource   = "http://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Recommendation",
  institution = "W3C",
}