@article{MM2_1982__38_154867,
     author = {Hartmut Pecher and Robert Glassey},
     title = {Time {Decay} for {Nonlinear} {Wave} {Equations} in {Two} {Space} {Dimensions.}},
     journal = {Manuscripta mathematica},
     pages = {387--400},
     publisher = {mathdoc},
     volume = {38},
     year = {1982},
     zbl = {0504.35066},
     url = {http://geodesic.mathdoc.fr/item/MM2_1982__38_154867/}
}