@article{MAN_1957__133_160545,
     author = {H. Beckert},
     title = {Existenzbeweise mehrdimensionaler regul\"arer {Variationsprobleme.}},
     journal = {Mathematische Annalen},
     pages = {191--218},
     publisher = {mathdoc},
     volume = {133},
     year = {1957},
     zbl = {0084.31702},
     url = {http://geodesic.mathdoc.fr/item/MAN_1957__133_160545/}
}