\documentclass[nojss]{jss}
\Abstract{\citet{R}}

\begin{document}

<<bib, echo=FALSE>>=
mybibentry <- citation()
mybibentry$key <- "R"
mybibentry$note <- R.version.string
writeLines(toBibtex(mybibentry), "jss.bib")
@
\bibliography{jss}

\end{document}