@article{EUA_1989-1990__3_a58,
     author = {G. Polya},
     title = {E\ensuremath{\pi}\ensuremath{\alpha}\ensuremath{\gamma}\ensuremath{\omega}\ensuremath{\gamma}\ensuremath{\acute\eta}},
     journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} A
},
     pages = {39-53},
     publisher = {mathdoc},
     volume = {3},
     year = {1989-1990},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/EUA_1989-1990__3_a58/}
}