C.I.G.R.E. <br/><br/>
CE/SC 34 GT/WG 09-1989: Digital Protection Techniques and Substation Functions. Working group 01 of study committee 34 (Protection) Sept. 1989 

 - Paris  CIGRE  Sept.1989 
 - 176 
<br/><br/><label>Universal Decimal Class. No.: </label>621.316.9  / CIG.89