@article{MZ_1954__60_169437,
     author = {Waldemar Velte},
     title = {Zur {Variationsrechnung} mehrfacher {Integrale.}},
     journal = {Mathematische Zeitschrift},
     pages = {367--383},
     year = {1954},
     volume = {60},
     zbl = {0057.08902},
     url = {http://geodesic.mathdoc.fr/item/MZ_1954__60_169437/}
}