@article{JRAM_1989__394_153109,
     author = {Albrecht Pfister},
     title = {Systeme quadratischer {Formen} {III.}},
     journal = {Journal f\"ur die reine und angewandte Mathematik},
     pages = {208--220},
     publisher = {mathdoc},
     volume = {394},
     year = {1989},
     zbl = {0652.10017},
     url = {http://geodesic.mathdoc.fr/item/JRAM_1989__394_153109/}
}