@article{MZ_1926__24_174980,
     author = {L. Koschmieder},
     title = {Invarianten bei der {Variation} vielfacher {Integrale}},
     journal = {Mathematische Zeitschrift},
     pages = {181--190},
     publisher = {mathdoc},
     volume = {24},
     year = {1926},
     zbl = {51.0376.03},
     url = {http://geodesic.mathdoc.fr/item/MZ_1926__24_174980/}
}