TY  - BOOK
AU  - Hellwig,Gunter
AU  - Hellwig,Birgitta
TI  - Differential operators of mathematical physics : An introduction
T2  - (Addison - wesley series in mathematics)
AV  - QA432 H45 1967 
PY  - 1967///
CY  - Reading Massachusets
PB  - Addison-wesley, 
KW  - Lemb
KW  - Física matemática
N1  - Incluye apéndice, bibliografía e índice
ER  -