Averaging methods in nonlinear dynamical systems  
Sanders, J. A. 
 - 2nd ed. 
 - New York :  Springer,  2007 
 - xxi, 431 p. :  ill. ;  24 cm. 
 - Applied mathematical sciences (Springer-Verlag New York Inc.) ;  v. 59 .
<br/><br/><label>ISBN: </label>9780387489162 | 0387489169