Prestel, A & Delzell, C.N <br/><br/>
Positive polynomials  from hilbert's 17th problem to real algebra 
A. Prestel & C.N Delzell 
 - Berlin  Springer  2001 
 - viii  267 
 - Springer monographs in mathematics .
<br/><br/><label>ISBN: </label>9783540412151