@article{MAN_1925__94_159106,
     author = {H. Brandt},
     title = {\"Uber die {Komponierbarkeit} quatern\"arer quadratischer {Formen}},
     journal = {Mathematische Annalen},
     pages = {179--197},
     year = {1925},
     volume = {94},
     zbl = {51.0130.11},
     url = {http://geodesic.mathdoc.fr/item/MAN_1925__94_159106/}
}