@article{AM2_1971__7_136253,
     author = {K.P. HADELER},
     title = {Non-Quadratic {Variational} {Problems}},
     journal = {Aequationes mathematicae},
     pages = {199--210},
     publisher = {mathdoc},
     volume = {7},
     year = {1971},
     zbl = {0232.49011},
     url = {http://geodesic.mathdoc.fr/item/AM2_1971__7_136253/}
}