PLATT, RICHARD <br/><br/>
CODE MAKING, CODE BREAKING 

 - LONDON :   COLLINS,   2011 
 - COLLINS BIG CAT : EMERALD, BAND 15 .
<br/><br/><label>ISBN: </label>9780007336449 
<br/><br/><label>Dewey Class. No.: </label>428.6 PLA