@article{10_4171_dm_3,
     author = {Detlev W. Hoffmann},
     title = {Twisted {Pfister} forms},
     journal = {Documenta mathematica},
     pages = {67--102},
     year = {1996},
     volume = {1},
     doi = {10.4171/dm/3},
     url = {http://geodesic.mathdoc.fr/articles/10.4171/dm/3/}
}