@article{MR_2004__61_a5, author = {B. N\ensuremath{\tau}\ensuremath{\zeta}\ensuremath{\iota}\ensuremath{\alpha}\ensuremath{\chi}\ensuremath{\rho}\ensuremath{\acute\eta}\ensuremath{\sigma}\ensuremath{\tau}o\ensuremath{\varsigma} and N. Z\ensuremath{\alpha}\ensuremath{\rho}\ensuremath{\acute\alpha}\ensuremath{\nu}\ensuremath{\eta}\ensuremath{\varsigma} and \ensuremath{\Gamma}. K\ensuremath{\alpha}\ensuremath{\rho}\ensuremath{\alpha}\ensuremath{\tau}\ensuremath{\rho}\ensuremath{\iota}\ensuremath{\acute\omega}\ensuremath{\tau}\ensuremath{\eta}\ensuremath{\varsigma}}, title = {H \ensuremath{\varepsilon}\ensuremath{\pi}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\rho}\ensuremath{\alpha}\ensuremath{\sigma}\ensuremath{\eta} \ensuremath{\varepsilon}\ensuremath{\kappa}\ensuremath{\pi}\ensuremath{\alpha}\ensuremath{\iota}\ensuremath{\delta}\ensuremath{\varepsilon}\ensuremath{\upsilon}\ensuremath{\tau}\ensuremath{\iota}\ensuremath{\kappa}o\ensuremath{\acute\upsilon} \ensuremath{\lambda}o\ensuremath{\gamma}\ensuremath{\iota}\ensuremath{\sigma}\ensuremath{\mu}\ensuremath{\iota}\ensuremath{\kappa}o\ensuremath{\acute\upsilon} \ensuremath{\beta}\ensuremath{\alpha}\ensuremath{\sigma}\ensuremath{\iota}\ensuremath{\sigma}\ensuremath{\mu}\ensuremath{\acute\epsilon}\ensuremath{\nu}o\ensuremath{\upsilon} \ensuremath{\sigma}\ensuremath{\tau}o \ensuremath{\mu}o\ensuremath{\nu}\ensuremath{\tau}\ensuremath{\acute\epsilon}\ensuremath{\lambda}o {Van} {Hiele} \ensuremath{\sigma}\ensuremath{\tau}\ensuremath{\eta} \ensuremath{\sigma}\ensuremath{\upsilon}\ensuremath{\nu}\ensuremath{\varepsilon}\ensuremath{\iota}\ensuremath{\sigma}\ensuremath{\varphi}o\ensuremath{\rho}\ensuremath{\acute\alpha} \ensuremath{\tau}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\alpha}\ensuremath{\nu}\'{o}\ensuremath{\tau}\ensuremath{\eta}\ensuremath{\tau}\ensuremath{\alpha}\ensuremath{\varsigma} \ensuremath{\mu}\ensuremath{\alpha}\ensuremath{\theta}\ensuremath{\eta}\ensuremath{\tau}\ensuremath{\acute\omega}\ensuremath{\nu} \ensuremath{\sigma}\ensuremath{\varepsilon} \ensuremath{\gamma}\ensuremath{\varepsilon}\ensuremath{\omega}\ensuremath{\mu}\ensuremath{\varepsilon}\ensuremath{\tau}\ensuremath{\rho}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\epsilon}\ensuremath{\varsigma} \ensuremath{\acute\epsilon}\ensuremath{\nu}\ensuremath{\nu}o\ensuremath{\iota}\ensuremath{\varepsilon}\ensuremath{\varsigma} \ensuremath{\pi}o\ensuremath{\upsilon} \ensuremath{\delta}\ensuremath{\iota}\ensuremath{\delta}\ensuremath{\acute\alpha}\ensuremath{\sigma}\ensuremath{\kappa}o\ensuremath{\nu}\ensuremath{\tau}\ensuremath{\alpha}\ensuremath{\iota} \ensuremath{\gamma}\ensuremath{\iota}\ensuremath{\alpha} \ensuremath{\pi}\ensuremath{\rho}\ensuremath{\acute\omega}\ensuremath{\tau}\ensuremath{\eta} \ensuremath{\varphi}o\ensuremath{\rho}\ensuremath{\acute\alpha}.}, 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 = {82-91}, publisher = {mathdoc}, volume = {61}, year = {2004}, language = {gr}, url = {http://geodesic.mathdoc.fr/item/MR_2004__61_a5/} }