@article{MR_2001_56_a6,
     author = { },
     title = {A\ensuremath{\nu}\ensuremath{\alpha}\ensuremath{\delta}\ensuremath{\iota}\ensuremath{\acute\alpha}\ensuremath{\rho}\ensuremath{\theta}\ensuremath{\rho}\ensuremath{\omega}\ensuremath{\sigma}\ensuremath{\eta} {A\ensuremath{\nu}\ensuremath{\alpha}\ensuremath{\lambda}\ensuremath{\upsilon}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}o\ensuremath{\acute\upsilon}} {\ensuremath{\Pi}\ensuremath{\rho}o\ensuremath{\gamma}\ensuremath{\rho}\ensuremath{\acute\alpha}\ensuremath{\mu}\ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\tau}o\ensuremath{\varsigma}} \ensuremath{\gamma}\ensuremath{\iota}\ensuremath{\alpha} \ensuremath{\tau}\ensuremath{\alpha} {M\ensuremath{\alpha}\ensuremath{\theta}\ensuremath{\eta}\ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\alpha}} \ensuremath{\tau}o\ensuremath{\upsilon} {\ensuremath{\Gamma}\ensuremath{\upsilon}\ensuremath{\mu}\ensuremath{\nu}\ensuremath{\alpha}\ensuremath{\sigma}\ensuremath{\acute\iota}o\ensuremath{\upsilon}}},
     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 = {70--89},
     year = {2001},
     volume = {56},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/MR_2001_56_a6/}
}