@article{MZ_1995__219_2_174782,
     author = {Lars H\"ormander},
     title = {Symplectic classification of quadratic forms, and general {Mehler} formulas.},
     journal = {Mathematische Zeitschrift},
     pages = {413--450},
     publisher = {mathdoc},
     volume = {219},
     number = {2},
     year = {1995},
     zbl = {0829.35150},
     url = {http://geodesic.mathdoc.fr/item/MZ_1995__219_2_174782/}
}