@article{MZ_1981__176_183633,
     author = {Wolf von Wahl and Philip Brenner},
     title = {Global {Classical} {Solutions} of {Nonlinear} {Wave} {Equations.}},
     journal = {Mathematische Zeitschrift},
     pages = {87--122},
     publisher = {mathdoc},
     volume = {176},
     year = {1981},
     zbl = {0457.35059},
     url = {http://geodesic.mathdoc.fr/item/MZ_1981__176_183633/}
}