Otto Pünter
... that Swiss World War II spy Otto Pünter used crosswords and lemon juice as means of encryption?
... that Swiss World War<span id="mwCh4" typeof="mw:Entity"> </span>II spy <b id="mwCh8"><a href="./Otto_Pünter" id="mwCiA" rel="mw:WikiLink" title="Otto Pünter">Otto Pünter</a></b> used crosswords and lemon juice as means of <a href="./Encryption" id="mwCiE" rel="mw:WikiLink" title="Encryption">encryption</a>?