Blyton , Enid  <br/><br/>
The mystery of the strange messages :  

 - Egmont :   London ;  1957. 
 - 246 p ; 21 cm .  01 
 - 2025-05-27 
<br/><br/><label>ISBN: </label>9781405272384 
<br/><br/><label>Nat. Bib. No.: </label>0011206 
<br/><br/><label>Nat. Bib. Agency Control No.: </label>BLY 
<br/><br/><label>Universal Decimal Class. No.: </label>823