Methods and applications of singular perturbations : 
Verhulst, F. 
 - New York :  Springer,  2005 
 - xv, 324 p. :  ill. ;  25 cm. 
 - Texts in applied mathematics ;  50 .
<br/><br/><label>ISBN: </label>9780387229669 (acid-free paper) | 0387229663 (acid-free paper)