Bachem, Achim. <br/><br/>
Linear programming duality  an introduction to oriented matroids 
by Achim Bachem, Walter Kern 
 - Berlin  Springer-Verlag  1992 
 - 216p. 
 - Universitext .
<br/><br/><label>ISBN: </label>3540554173 
<br/><br/><label>Dewey Class. No.: </label>511.6  / N92