@article{EUG_1996_45_a8,
     author = {Kiriakie Kiriaki and  Zoi Rapti},
     title = {An {Extrerior} {Mixed} {Boundary} {Value} {Problem} for the {Helmholtz} {Equation}},
     journal = {E\ensuremath{\upsilon}\ensuremath{\kappa}\ensuremath{\lambda}\ensuremath{\varepsilon}\ensuremath{\acute\iota}\ensuremath{\delta}\ensuremath{\eta}\ensuremath{\varsigma} \ensuremath{\Gamma}},
     pages = {43--55},
     year = {1996},
     volume = {45},
     language = {gr},
     url = {http://geodesic.mathdoc.fr/item/EUG_1996_45_a8/}
}