<http://schema.org/keywords>
"\u65E5\u672C\u3067\u50CD\u304F\u300D\u3068\u3044\u3046\u3053\u3068"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.huffingtonpost.jp/2013/05/21/story_n_3311122.html>