@article{FORUM_1993__5_3_141715,
     author = {Jean-Claude Guillot and Benoit Gr\'ebert},
     title = {Gaps of one dimensional periodic {AKNS} systems.},
     journal = {Forum mathematicum},
     pages = {459--504},
     publisher = {mathdoc},
     volume = {5},
     number = {3},
     year = {1993},
     zbl = {0784.34024},
     url = {http://geodesic.mathdoc.fr/item/FORUM_1993__5_3_141715/}
}