Bartsch, T <br/><br/>
Topological methods for variational problems with symmetries 
T. Bartsch 
 - Berlin  Springer  1993 
 - x  152 
 - Lecture notes in mathematics 1560 .
<br/><br/><label>ISBN: </label>354057378x 
<br/><br/><label>Dewey Class. No.: </label>6.08+10.13+22  / BART