@article{EJDE_2008__2008__a27,
     author = {Kharibegashvili, Sergo and Midodashvili, Bidzina},
     title = {Solvability of characteristic boundary-value problems for nonlinear equations with iterated wave operator in the principal part},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {2008},
     year = {2008},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2008__2008__a27/}
}