@article{CMH_1933__5_138589,
     author = {C. Carath\'eodory},
     title = {Ueber die {Einteilung} der {Variationsprobleme} von {Lagrange} nach {Klassen.}},
     journal = {Commentarii mathematici Helvetici},
     pages = {1--19},
     publisher = {mathdoc},
     volume = {5},
     year = {1933},
     zbl = {0006.06004},
     url = {http://geodesic.mathdoc.fr/item/CMH_1933__5_138589/}
}