Blyton, Enid <br/><br/>
Five have a mystery to solve 

 - London  Knight books  1971 
 - 186 p. 
<br/><br/><label>ISBN: </label>221149 
<br/><br/><label>Subjects--Topical Terms: </label><br/>English fiction
<br/><br/><label>Dewey Class. No.: </label>823  / BLY