@article{MAN_1980__251_163426,
     author = {Victor Bangert},
     title = {Closed {Geodesics} on {Complete} {Surfaces.}},
     journal = {Mathematische Annalen},
     pages = {83--96},
     publisher = {mathdoc},
     volume = {251},
     year = {1980},
     zbl = {0422.53024},
     url = {http://geodesic.mathdoc.fr/item/MAN_1980__251_163426/}
}