@article{MR_2003_60_a0,
     author = {\ensuremath{\Gamma}. \ensuremath{\Delta}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\acute\alpha}\ensuremath{\kappa}o\ensuremath{\varsigma} and  \ensuremath{\Pi}. B\ensuremath{\lambda}\ensuremath{\acute\alpha}\ensuremath{\mu}o\ensuremath{\varsigma}},
     title = {\ensuremath{\Sigma}\ensuremath{\upsilon}\ensuremath{\gamma}\ensuremath{\kappa}\ensuremath{\rho}\ensuremath{\iota}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\eta} {A\ensuremath{\xi}\ensuremath{\iota}o\ensuremath{\lambda}\'{o}\ensuremath{\gamma}\ensuremath{\eta}\ensuremath{\sigma}\ensuremath{\eta}} {\ensuremath{\Delta}\ensuremath{\iota}\ensuremath{\delta}\ensuremath{\alpha}\ensuremath{\sigma}\ensuremath{\kappa}\ensuremath{\alpha}\ensuremath{\lambda}\ensuremath{\acute\iota}\ensuremath{\alpha}\ensuremath{\varsigma}} {M\ensuremath{\alpha}\ensuremath{\theta}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\omega}\ensuremath{\nu}} \ensuremath{\sigma}\ensuremath{\tau}o {\ensuremath{\Sigma}\ensuremath{\upsilon}\ensuremath{\mu}\ensuremath{\beta}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\'{o}} {\ensuremath{\Pi}\ensuremath{\alpha}\ensuremath{\nu}\ensuremath{\varepsilon}\ensuremath{\pi}\ensuremath{\iota}\ensuremath{\sigma}\ensuremath{\tau}\ensuremath{\acute\eta}\ensuremath{\mu}\ensuremath{\iota}o} \ensuremath{\kappa}\ensuremath{\alpha}\ensuremath{\iota} {\ensuremath{\sigma}\ensuremath{\tau}\ensuremath{\eta}\ensuremath{\nu}A\ensuremath{\nu}o\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\tau}\ensuremath{\acute\eta}} \ensuremath{\kappa}\ensuremath{\alpha}\ensuremath{\iota} \ensuremath{\varepsilon}\ensuremath{\xi} \ensuremath{\alpha}\ensuremath{\pi}o\ensuremath{\sigma}\ensuremath{\tau}\ensuremath{\acute\alpha}\ensuremath{\sigma}\ensuremath{\varepsilon}\ensuremath{\omega}\ensuremath{\varsigma} \ensuremath{\varepsilon}\ensuremath{\kappa}\ensuremath{\pi}\ensuremath{\alpha}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\varepsilon}\ensuremath{\upsilon}\ensuremath{\sigma}\ensuremath{\eta}},
     journal = {M\ensuremath{\alpha}\ensuremath{\theta}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\eta} E\ensuremath{\pi}\ensuremath{\iota}\ensuremath{\theta}\ensuremath{\varepsilon}\ensuremath{\acute\omega}\ensuremath{\rho}\ensuremath{\eta}\ensuremath{\sigma}\ensuremath{\eta}},
     pages = {7--19},
     year = {2003},
     volume = {60},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/MR_2003_60_a0/}
}