<http://schema.org/keywords>
"\u30E2\u30CF\u30E1\u30C9\u30FB\u30A2\u30EA \u30AA\u30D0\u30DE\u5927\u7D71\u9818"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.huffingtonpost.jp/2016/06/04/obama-on-the-passing-of-muhammad-ali_n_10302588.html>