@article{MZ_1924__20_167797,
     author = {H. Brandt},
     title = {Bilineare {Transformation} quatern\"arer quadratischer {Formen}},
     journal = {Mathematische Zeitschrift},
     pages = {223--230},
     publisher = {mathdoc},
     volume = {20},
     year = {1924},
     zbl = {50.0054.02},
     url = {http://geodesic.mathdoc.fr/item/MZ_1924__20_167797/}
}