@article{MM2_1974__13_154263,
     author = {Wolf von Wahl},
     title = {Regular {Solutions} of {Initial-Boundary} {Value} {Problems} for {Linear} and {Nonlinear} {Wave} - {Equations} {I.}},
     journal = {Manuscripta mathematica},
     pages = {187--206},
     publisher = {mathdoc},
     volume = {13},
     year = {1974},
     zbl = {0289.35053},
     url = {http://geodesic.mathdoc.fr/item/MM2_1974__13_154263/}
}