The G8 system and the G20/  Evolution,role and documentation 
Hajnal, Peter I. 
 - Englang:  Ashgate Publshing,  2007. 
 - 277 p. 
<br/><br/><label>ISBN: </label>9780754645504 
<br/><br/><label>Dewey Class. No.: </label>337.1  / HAJ/G