Helffer Bernard <br/><br/>
Hypoelliptic Estimates and Spectral Theory for Fokker Planck Operators and Witten Laplacians 
/ by Bernard Helffer 
 - New York  Springer  2005 
 - 209p. 
<br/><br/><label>ISBN: </label>3540242007 
<br/><br/><label>Dewey Class. No.: </label>515.7222  / HEL/H