TY  - BOOK
AU  - Hellwig,Gunter
TI  - Partial differential equations: an introduction 
U1  - 517.383 
PY  - 1964///
CY  - New York
PB  - Blaisdell Pub.
KW  - Differential equations, Partial
N1  - Translated from the German; Includes bibliographical references and index
ER  -