\begin{thebibliography}{ORPA00}

\bibitem[ORPA00]{Ourselin_MICCAI_2000}
S.~Ourselin, A.~Roche, S.~Prima, and N.~Ayache.
\newblock Block matching: A general framework to improve robustness of rigid
  registration of medical images.
\newblock In {\em MICCAI '00}, volume 1935 of {\em LNCS}, pages 557--566, 2000.

\bibitem[PFA04]{Pennec_report_2004}
Xavier Pennec, Pierre Fillard, and Nicholas Ayache.
\newblock A {R}iemannian {F}ramework for {T}ensor {C}omputing.
\newblock Technical report, INRIA, July 2004.

\end{thebibliography}