@article{MZ_1989__201_4_174033,
     author = {Philip Brenner},
     title = {On {Space-Time} {Means} and {Strong} {Global} {Solutions} of {Nonlinear} {Hyperbolic} {Equations.}},
     journal = {Mathematische Zeitschrift},
     pages = {45--56},
     publisher = {mathdoc},
     volume = {201},
     number = {4},
     year = {1989},
     zbl = {0705.35082},
     url = {http://geodesic.mathdoc.fr/item/MZ_1989__201_4_174033/}
}