@Article{zbMATH03113744,
Author = {Peter D. {Lax}},
Title = {{On Cauchy's problem for hyperbolic equations and the differentiability of solutions of elliptic equations}},
FJournal = {{Communications on Pure and Applied Mathematics}},
Journal = {{Commun. Pure Appl. Math.}},
ISSN = {0010-3640; 1097-0312/e},
Volume = {8},
Pages = {615--633},
Year = {1955},
Publisher = {Wiley, Hoboken, NJ},
Language = {English},
Zbl = {0067.07502}
}