@article{MZ_1973__131_171898,
     author = {Richard Elman and Tsit-Yuen Lam},
     title = {Quadratic {Forms} and the {u-Invariant.} {I.}},
     journal = {Mathematische Zeitschrift},
     pages = {283--304},
     publisher = {mathdoc},
     volume = {131},
     year = {1973},
     zbl = {0244.10020},
     url = {http://geodesic.mathdoc.fr/item/MZ_1973__131_171898/}
}