@article{MZ_1995__219_2_174754,
     author = {Vladimir Georgiev and Pedro P. Schirmer},
     title = {Global existence of low regularity solutions of non-linear wave equations.},
     journal = {Mathematische Zeitschrift},
     pages = {1--20},
     publisher = {mathdoc},
     volume = {219},
     number = {2},
     year = {1995},
     zbl = {0824.35074},
     url = {http://geodesic.mathdoc.fr/item/MZ_1995__219_2_174754/}
}