@article{MAN_1908__65_158364,
     author = {M. Mason},
     title = {On the linear differential equation of hyperbolic type},
     journal = {Mathematische Annalen},
     pages = {570--576},
     year = {1908},
     volume = {65},
     zbl = {39.0427.01},
     url = {http://geodesic.mathdoc.fr/item/MAN_1908__65_158364/}
}