Ambrosetti, A & Zelati, V.C <br/><br/>
Periodic solutions of singular lagrangian systems 
A. Ambrosetti & V.C. Zelati 
 - Boston  Birkhauser-Verlag  1993 
 - xii  157 
 - Progress in nonlinear differential equations & their applications 10 .
<br/><br/><label>ISBN: </label>9780817636555 
<br/><br/><label>Dewey Class. No.: </label>12.01+6.08  / AMBR