title: Filtering results of SPARQL queries
body: <p>I want to retrieve all 20th century italian novelists' name.
  I've written this:</p>
  
  <p><code>SELECT ?label
  WHERE{
  ?novelist a yago:ItalianNovelists.
  ?novelist rdfs:label ?label.
  FILTER (langMatches(lang(?label), "EN"))
  }
  ORDER BY ?label</code></p>
  
  <p>How can i filter the results?</p>