@article{MM2_1993__81_3-4_155885,
     author = {Nakao Hayashi},
     title = {Global existence of small radially symmetric solutions to quadratic nonlinear wave equations in an exterior domain.},
     journal = {Manuscripta mathematica},
     pages = {15--40},
     publisher = {mathdoc},
     volume = {81},
     number = {3-4},
     year = {1993},
     zbl = {0816.35088},
     url = {http://geodesic.mathdoc.fr/item/MM2_1993__81_3-4_155885/}
}