% knitr -> PDFLaTeX in WinEdt 10.2 with RManager plugin
% http://www.winedt.org/config/modes/RManager.html
documentclass[a4paper,10pt]{article}
usepackage[utf8]{inputenc}
usepackage[T1]{fontenc}
usepackage[margin=2.5cm]{geometry}
usepackage[style=authoryear,backend=biber]{biblatex}
addbibresource{mybibfile.bib}

% This is the R code chunk
<<Preamble,include=FALSE>>=
# install the R packages, if they are not already installed.
#install.packages("rcrossref",dependencies=True)
#install.packages("patchDVI",dependencies=True)

# load knitr and rcrossref
library(knitr)
library(rcrossref)

# nominate the DOIs of interest
mydois <- c('10.1002/andp.19053221004',
'10.1038/171737a0',
'10.1038/227680a0',
'10.1103/PhysRevB.37.785')

# extract the metadata for each DOI from Crossref and write the bib file
for(i in 1:4) {
     x <- cr_cn(dois=mydois[i], format = "bibtex")
     write.table(x,file="mybibfile.bib",append=TRUE,row.names=FALSE,col.names=FALSE,fileEncoding="UTF-8")
}
@
% Print the bibliography
begin{document}
nocite{*}
printbibliography
end{document}