@article{MZ_1973__133_171962,
     author = {A. Prestel},
     title = {Quadratische {Semi-Ordnungen} und {Quadratische} {Formen.}},
     journal = {Mathematische Zeitschrift},
     pages = {319--342},
     publisher = {mathdoc},
     volume = {133},
     year = {1973},
     zbl = {0275.12013},
     url = {http://geodesic.mathdoc.fr/item/MZ_1973__133_171962/}
}