Bogaevski, V. N.  <br/><br/>
Algebraic methods in nonlinear perturbation theory 
/ by V. N. Bogaevski & A. Povzner 
 - New York  Springer  1991 
 - 265p. 
<br/><br/><label>Dewey Class. No.: </label>515.35  / BOG/A