@article{JRAM_1997__491_153949,
     author = {Robert A. Gardner},
     title = {Spectral analysis of long wavelength periodic waves and applications.},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {149--182},
     year = {1997},
     volume = {491},
     zbl = {0883.35055},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1997__491_153949/}
}