@article{GDZPPN002347431, title = {\"Uber sachgem\"a\ss e Cauchyprobleme.}, journal = {Mathematica Scandinavica}, volume = {13}, year = {1963}, pages = {109-128}, zbl = {0145.13303}, url = {http://dml.mathdoc.fr/item/GDZPPN002347431} }
Kreiss, Hans-Otto. Über sachgemäße Cauchyprobleme.. Mathematica Scandinavica, Tome 13 (1963) pp. 109-128. http://gdmltest.u-ga.fr/item/GDZPPN002347431/