O'Regan, Donal <br/><br/>
Topological degree theory and applications 

 - Boca Raton  Chapman & Hall/CRC  2006 
 - Series in mathematical analysis and applications .
<br/><br/><label>ISBN: </label>158488648X 
<br/><br/><label>Dewey Class. No.: </label>514.2/ORE