@article{MZ_1996__222_3_174888,
     author = {Tohru Ozawa and Y. Tsutsumi and K. Tsutaya},
     title = {Global existence and asymptotic behavior of solutions for the {Klein-Gordon} equations with quadratic nonlinearity in two space dimensions.},
     journal = {Mathematische Zeitschrift},
     pages = {341--362},
     publisher = {mathdoc},
     volume = {222},
     number = {3},
     year = {1996},
     zbl = {0877.35030},
     url = {http://geodesic.mathdoc.fr/item/MZ_1996__222_3_174888/}
}