@article{EJDE_1999__1999__a74,
     author = {Aberra, Dawit},
     title = {On a generalized reflection law for functions satisfying the {Helmholtz} equation},
     journal = {Electronic Journal of Differential Equations},
     publisher = {mathdoc},
     volume = {1999},
     year = {1999},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_1999__1999__a74/}
}