CIGRE <br/><br/>
CIGRE: 64 - 1991; Application guide on protection of complex transmission network configurations; working group 04 of study committee 34 (Protection) 

 - paris  CIGRE  1991 
 - 153 
<br/><br/> Taken print out from website 
<br/><br/><label>Universal Decimal Class. No.: </label>621.315.011.7  / CIG.91