@article{MR_1992__38_a20,
     author = {Constantinos N. Yatras},
     title = {Characteristic of {M-polysymmetrical} {Hyperrings} and some properties of {M-Polysymmetrical} {Hyperrings} with {Unity}},
     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 = {115-125},
     publisher = {mathdoc},
     volume = {38},
     year = {1992},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/MR_1992__38_a20/}
}