@article{AM2_1974__11_136456,
     author = {Peter Volkmann},
     title = {Eine {Charakterisierung} der positiv definiten quadratischen {Formen.}},
     journal = {Aequationes mathematicae},
     pages = {174--182},
     publisher = {mathdoc},
     volume = {11},
     year = {1974},
     zbl = {0289.39006},
     url = {http://geodesic.mathdoc.fr/item/AM2_1974__11_136456/}
}