@article{PORMA_1963__22_4_114908,
     author = {Samelson, Hans},
     title = {On manifolds with many closed geodesics},
     journal = {Portugaliae mathematica},
     pages = {193--196},
     publisher = {mathdoc},
     volume = {22},
     number = {4},
     year = {1963},
     mrnumber = {0230256},
     zbl = {0134.17704},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1963__22_4_114908/}
}