Helms, Lester L. <br/><br/>
Potential theory 
by Lester L helms 
 - 2nd ed. 
 - London  Springer  2014 
 - xiv, 485p. 
 - Universitext   .
<br/><br/><label>ISBN: </label>9781447164210 
<br/><br/><label>Dewey Class. No.: </label>515.96  / P14