McKay, Sinclair. <br/><br/>
Secret Agent Brainteasers: More Than 100 Codebreaking Puzzles Inspired by Britain&#039;s Espionage Masterminds. 

 - 288  p. 
<br/><br/> Secret Agent Brainteasers: More Than 100 Codebreaking Puzzles Inspired by Britain&#039;s Espionage Masterminds by Sinclair McKay (2019) 
<br/><br/><label>ISBN: </label>1635061350