\input zb-basic
\input zb-ioport
\iteman{io-port 50359421}
\itemau{Arsigny, Vincent; Fillard, Pierre; Pennec, Xavier; Ayache, Nicholas}
\itemti{Geometric means in a novel vector space structure on symmetric positive-definite matrices}
\itemso{SIAM J. Matrix Analysis Applications 29, No. 1, 328-347 (2006).}
\itemcc{}
\itemut{}
\itemli{doi:10.1137/050637996}
\end