@article{JRAM_1908__134_149288,
     author = {Philipp Frank},
     title = {\"Uber die {Bahnkurven} der {Mechanik.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {156--166},
     publisher = {mathdoc},
     volume = {134},
     year = {1908},
     zbl = {39.0769.02},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1908__134_149288/}
}