@article{CMH_1934__6_138605,
     author = {Fridolin B\"abler},
     title = {\"Uber die {Existenz} von {L\"osungen} zu {Variationsproblemen} n-ter {Ordnung.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {1--27},
     publisher = {mathdoc},
     volume = {6},
     year = {1934},
     zbl = {0007.11802},
     url = {http://geodesic.mathdoc.fr/item/CMH_1934__6_138605/}
}