\subsection{Image Sources}
\begin{frame}{Image Sources}
    \begin{itemize}
	\item \href{https://commons.wikimedia.org/wiki/File:PageRank-hi-res.png}{PageRank} by Felipe Micaroni Lalli
	\item screenshots of \href{http://www.dmoz.org}{www.dmoz.org}
	\item \href{https://commons.wikimedia.org/wiki/File:Hyperlink-Wikipedia.svg}{Hyperlink} by Bernard Ladenthin
	\item screenshots of \href{http://dontbubble.us}{dontbubble.us}
        \item \href{http://commons.wikimedia.org/wiki/File:Sergey_Brin.JPG}{Sergey Brin} by enlewof
        \item \href{http://commons.wikimedia.org/wiki/File:Larry_Page_laughs.jpg}{Larry Page} by aweigend
    \end{itemize}
\end{frame}