@article{MAN_1935__111_159762,
     author = {G. Hamel},
     title = {Das {Hamiltonsche} {Prinzip} bei nichtholonomen {Systemen.}},
     journal = {Mathematische Annalen},
     pages = {94--97},
     publisher = {mathdoc},
     volume = {111},
     year = {1935},
     zbl = {0010.42101},
     url = {http://geodesic.mathdoc.fr/item/MAN_1935__111_159762/}
}