TY  - BOOK
AU  - Murdock James A
TI  - Perturbations: theory and methods
U1  - B3310t4, N1 
PY  - 1991///
CY  - New York    
PB  -  John Wiley       
KW  -  Numerical solution
KW  -  Ordinary differential equations
KW  - Mathematics
ER  -