@article{10_1017_S0017089500000707,
     author = {Young, Eutiquio C.},
     title = {Riemann's method and the characteristic value and cauchy problems for the damped wave equation{\textdagger}},
     journal = {Glasgow mathematical journal},
     pages = {147--152},
     year = {1969},
     volume = {10},
     number = {2},
     doi = {10.1017/S0017089500000707},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0017089500000707/}
}