@article{IM_1978__45_142546,
     author = {Robert L. Devaney},
     title = {Collision {Orbits} in the {Anisotropic} {Kepler} {Problem.}},
     journal = {Inventiones mathematicae},
     pages = {221--252},
     publisher = {mathdoc},
     volume = {45},
     year = {1978},
     zbl = {0382.58015},
     url = {http://geodesic.mathdoc.fr/item/IM_1978__45_142546/}
}