@article{IM_1977__43_142513,
     author = {Akio Kawauchi},
     title = {On {Quadratic} {Forms} in {3-Manifolds.}},
     journal = {Inventiones mathematicae},
     pages = {177--198},
     year = {1977},
     volume = {43},
     zbl = {0365.57001},
     url = {http://geodesic.mathdoc.fr/item/IM_1977__43_142513/}
}