Giacaglia G.E.O. <br/><br/>
Perturbation Methods in Non-Linear Systems 
Giacaglia G.E.O. 
 - New York etc.  Springer-Verlag  1972 
 - 369 p. 
<br/><br/> Applied Mathematical Sciences V.8 
<br/><br/><label>Dewey Class. No.: </label>517.912+517.957