\documentclass{article}
\usepackage{pdfpages}
%\VignetteIndexEntry{RcppGSL}
%\VignetteKeywords{R,GSL,Rcpp,data transfer}
%\VignettePackage{RcppGSL}
%\VignetteDepends{RcppGSL}
%\VignetteEncoding{UTF-8}

\begin{document}
\includepdf[pages=-, fitpaper=true]{RcppGSL-introduction.pdf}
\end{document}