", GCHQ; Cambridge, HRH The Duchess of; Hannigan, Robert" <br/><br/>
The GCHQ Puzzle Book: Perfect for anyone who likes a good headscratcher 

 - 1st 
 - 336p    cm 24 
<br/><br/><label>ISBN: </label>978 0718185541 
<br/><br/><label>Dewey Class. No.: </label>793.73  /  G 5742