Reference for “SPARQL 1.1 Query”

@TechReport{Seaborne:09:SQ,
  author      = "Andy Seaborne and Steve Harris",
  title       = "{SPARQL} 1.1 Query",
  month       = oct,
  note        = "http://www.w3.org/TR/2009/WD-sparql11-query-20091022/",
  year        = "2009",
  bibsource   = "http://w2.syronex.com/jmr/w3c-biblio",
  type        = "{W3C} Working Draft",
  institution = "W3C",
}