TY  - BOOK
AU  - Stephani,Hans
AU  - MacCallum,M.A.H.
TI  - Differential equation: their solution symmetries 
SN  - 0521366895
PY  - 1989///
CY  - Cambridge
PB  - Cambridge University Press
KW  - Differential equations
KW  - Numerical solutions
KW  - Symmetry
ER  -