Flowers, T. H. <br/><br/>
Introduction to exchange systems   
by T. H. Flowers. 
 - London  John Wiley & Sons  1976 
 - xvii, 326p. 
<br/><br/><label>ISBN: </label>0471018651 
<br/><br/><label>Dewey Class. No.: </label>621.3854  / N76