@article{DOCMA_2003__8__a3,
     author = {Frank, Rupert L.},
     title = {On the scattering theory of the {Laplacian} with a periodic boundary condition. {I.} {Existence} of wave operators},
     journal = {Documenta mathematica},
     pages = {547--565},
     publisher = {mathdoc},
     volume = {8},
     year = {2003},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DOCMA_2003__8__a3/}
}