@article{MAN_1990__288_1_164745,
     author = {H. Hofer and K. Wysocki},
     title = {First order elliptic systems and the existence of homoclinic orbits in {Hamiltonian} systems.},
     journal = {Mathematische Annalen},
     pages = {483--504},
     publisher = {mathdoc},
     volume = {288},
     number = {1},
     year = {1990},
     zbl = {0702.34039},
     url = {http://geodesic.mathdoc.fr/item/MAN_1990__288_1_164745/}
}