<http://schema.org/mainEntityOfPage>
<http://www.tweaktown.com/news/24189/facebook_ipo_is_first_to_trade_500m_shares_in_first_day/index.html>
<http://www.tweaktown.com/news/24189/facebook_ipo_is_first_to_trade_500m_shares_in_first_day/index.html>