Logo of the <a href="https://en.wikipedia.org/wiki/Blackstone_Group" class="extiw" title="en:Blackstone Group">Blackstone Group</a>.
Source: <a rel="nofollow" class="external free" href="http://www.blackstone.com/news/press_releases/3-10-2008.pdf">http://www.blackstone.com/news/press_releases/3-10-2008.pdf</a>