\documentclass{article}
\usepackage{pdfpages}
%\VignetteIndexEntry{RProtoBuf-paper}
%\VignetteKeywords{RProtoBuf, Protocol Buffers, package}
%\VignetteDepends{RProtoBuf}
%\VignetteEncoding{UTF-8}

\begin{document}
\includepdf[pages=-, fitpaper=true]{pdf/RProtoBuf-paper.pdf}
\end{document}