Nayfeh, Ali Hasan. <br/><br/>
Perturbation methods   
by Ali Hasan Nayfeh. 
 - New York  Wiley  1973 
 - xii, 426p 
 - Pure and Applied Mathematics .
<br/><br/><label>ISBN: </label>0471630594 
<br/><br/><label>Dewey Class. No.: </label>515.72  / N731;1