\documentclass{article}

\usepackage[backend=bibtex]{biblatex}
\addbibresource{biblatex-bib1}
\addbibresource{biblatex-bib2}

\begin{document}

\input{biblatex-sub}

Some text.

\end{document}

%%% Local Variables:
%%% mode: LaTeX
%%% TeX-master: t
%%% End: