@article{1183516230,
author = {Erd\'elyi, A.},
title = {The analytic theory of systems of partial differential equations},
journal = {Bull. Amer. Math. Soc.},
volume = {57},
number = {6},
year = {1951},
pages = { 339-353},
language = {en},
url = {http://dml.mathdoc.fr/item/1183516230}
}
Erdélyi, A. The analytic theory of systems of partial differential equations. Bull. Amer. Math. Soc., Tome 57 (1951) no. 6, pp. 339-353. http://gdmltest.u-ga.fr/item/1183516230/