\documentclass[10pt,a4paper]{book}
\usepackage{xltxtra}
\usepackage{biblatex}
\usepackage{polyglossia}
\setdefaultlanguage{spanish}
\setmainfont[Mapping=tex-text]{Charis SIL}
\bibliography{espagnol}
\renewcommand{\newunitpunct}{\addcomma\space}

\title{}
\author{}
\date{}

\begin{document}
\maketitle

\printbibliography
	\nocite{ory_india}
	\nocite{weinberger_india}
	\nocite{giraud_tantrisme}
	\nocite{briante_mono}

\end{document}