<http://schema.org/mainEntityOfPage>
<http://www.huffingtonpost.com/2011/01/06/katy-perry-how-i-met-your-mother-guest-star_n_805207.html>
<http://www.huffingtonpost.com/2011/01/06/katy-perry-how-i-met-your-mother-guest-star_n_805207.html>