[R] Sweave and bibliographies

[Terry Therneau]

 I added a bibliographic reference to one of my .Rnw documents, to wit:

\begin{thebibliography}{9}
  \bibitem{Jose} Jos{\'{e}} C. Pinheiro and Douglas M. Bates,
    \emph{Mixed-Effects Models in S and S-PLUS},
    Springer, 2000.
\end{thebibliography}

just before the \end{document}.
When I run Sweave on the result these lines disappear without a trace.

Is this intentional?  

Subquestion: is there a link to some Sweave documentation from the main CRAN
or R page?

Terry T.