34XX 


Ordinary differential equations 

34Exx 

Asymptotic theory 


34E05 
Asymptotic expansions 


34E10 
Perturbations, asymptotics 


34E13 
Multiple scale methods 


34E15 
Singular perturbations, general theory 


34E17 
Canard solutions 


34E18 
Methods of nonstandard analysis 


34E20 
Singular perturbations, turning point theory, WKB methods 


34E99 
None of the above, but in this section 