Change page layout in the middle of a LaTeX document

I'm looking for a way to change some page layout dimensions in the middle of a LaTeX document. The reason is, I'd like to have smaller margins and longer lines in the "References" section of my report document (basically because short lines aren't so important there and I can save space).

In my preamble I have (works fine):

\setlength\textwidth{130mm}
\setlength\oddsidemargin{14.6mm}

In the document I simply try to re-set them at the right point but they're ignored.

... last paragraph ends here.

\newpage
\setlength\textwidth{150mm}      % +20mm text width
\setlength\oddsidemargin{13.6mm} % -10mm left margin (so it stays centered)

References ...

The geometry package is useful but only for global adjustments in the preamble, so I can't use it here. Is it not possible to change the page layout at some point in the document?