Riordan, Rick. <br/><br/>
The demigod files 
Rick Riordan 
 - 1st ed. 
 - [S.l.]  Disney/Hyperion Books  2009 
 - 151 p. 
 - Percy Jackson and the Olympians .
 - Percy Jackson and the Olympians .
<br/><br/><label>ISBN: </label>9781423121664