@article{MR_1979_15_a15,
     author = {Grigorios Tsagas},
     title = {On the {Surfaces} {Whose} {Normal} {Bundles} {Have} {Special} {Properties}},
     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 = {59--67},
     year = {1979},
     volume = {15},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/MR_1979_15_a15/}
}