\documentclass[a4paper]{article}
\usepackage[a4paper, total={20cm, 27cm}]{geometry}
\pagestyle{empty}
\usepackage[utf8]{inputenc}
\usepackage{hyperref}
\usepackage[
%backend=biber,
backend=bibtex,
style=reading,
sorting=ydnt,
defernumbers=true
]{biblatex}
\addbibresource{/GW/root/bibtex/golem}
\addbibresource{/GW/root/bibtex/castor}
\title{The GOLEM tokamak bibliography}
\author{The tokamak GOLEM team}
%\date{}
\defbibfilter{golemarticles}{
type=article and
keyword={exp.plasmaedge}
and keyword={golem}
}
\defbibfilter{castorarticles}{
type=article and
keyword={exp.plasmaedge}
and keyword={castor}
}
\begin{document}
\maketitle
\nocite{*}
\section{GOLEM Articles}
\printbibliography[filter=golemarticles, title={}]
\section{CASTOR articles}
\printbibliography[filter=castorarticles, title={}]
%\printbibliography[type=inproceedings,title={Conference proceedings}]
%\printbibliography[keyword=mathesis,title={Master thesis}]
%\printbibliography[keyword=bachproj,title={Bachelor projects}]
%\printbibliography[keyword=soc,title={High School Students` Professional Activities}]
%\printbibliography[type=misc,keyword=in, title={Miscellaneous}]
%\printbibliography[type=article,keyword=out,title={Unofficial articles (without GOLEM cooperation/authors)}]
%\printbibliography[title={The tokamak GOLEM bibliography}]
\end{document}
