@article{MR_1977_6_a3,
     author = {I. G. Petrofskiy},
     title = {\ensuremath{\Sigma}\ensuremath{\upsilon}\ensuremath{\nu}\ensuremath{\eta}\ensuremath{\theta}\ensuremath{\iota}\ensuremath{\sigma}\ensuremath{\mu}\ensuremath{\acute\epsilon}\ensuremath{\nu}\ensuremath{\varepsilon}\ensuremath{\varsigma} {\ensuremath{\Delta}\ensuremath{\iota}\ensuremath{\alpha}\ensuremath{\varphi}o\ensuremath{\rho}\ensuremath{\iota}\ensuremath{\kappa}\ensuremath{\acute\epsilon}\ensuremath{\varsigma}} {E\ensuremath{\xi}\ensuremath{\iota}\ensuremath{\sigma}\ensuremath{\acute\omega}\ensuremath{\sigma}\ensuremath{\varepsilon}\ensuremath{\iota}\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 = {77--139},
     year = {1977},
     volume = {6},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/MR_1977_6_a3/}
}