TY  - BOOK
AU  - Keng Hua Loo
AU  -  Ci-Quian Wu
AU  -  Wei Lin
TI  - Second-order systems of partial differential equations of the plane
T2  - Research notes in mathematics; 128
U1  - B334, M5 
PY  - 1985///
CY  - Boston
PB  - Pitman         
KW  - Differential equations
N1  - Includes bibliography
ER  -