@article{MR_1987_32_a0,
     author = {Felix Klein},
     title = {\ensuremath{\Gamma}\ensuremath{\iota}\ensuremath{\alpha} \ensuremath{\tau}\ensuremath{\eta}\ensuremath{\nu} {I\ensuremath{\sigma}\ensuremath{\tau}o\ensuremath{\rho}\ensuremath{\acute\iota}\ensuremath{\alpha}} \ensuremath{\tau}\ensuremath{\omega}\ensuremath{\nu} {\ensuremath{\Theta}\ensuremath{\varepsilon}\ensuremath{\mu}\ensuremath{\varepsilon}\ensuremath{\lambda}\ensuremath{\acute\iota}\ensuremath{\omega}\ensuremath{\nu}} \ensuremath{\tau}\ensuremath{\eta}\ensuremath{\varsigma} {\ensuremath{\Gamma}\ensuremath{\varepsilon}\ensuremath{\omega}\ensuremath{\mu}\ensuremath{\varepsilon}\ensuremath{\tau}\ensuremath{\rho}\ensuremath{\acute\iota}\ensuremath{\alpha}\ensuremath{\varsigma}}},
     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 = {3--12},
     year = {1987},
     volume = {32},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/MR_1987_32_a0/}
}