<http://schema.org/url>
<http://www.businessweek.com/articles/2013-02-20/yammer-earns-its-keep-for-microsoft-one-kahlua-sundae-at-a-time>
<http://www.bloomberg.com/bw/articles/2013-02-20/yammer-earns-its-keep-for-microsoft-one-kahlua-sundae-at-a-time>