<http://schema.org/keywords>
"\u30B9\u30C8\u30EA\u30FC\u30C8\u30D3\u30E5\u30FC"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.huffingtonpost.jp/2013/06/27/burj_khalifa_google_street_view_n_3508813.html>