The ARRL Handbook for Radio Amateurs/ 

 - 68th ed. 
 - New York  The American Radio Relay League  1990 
 - various pages:  ill.; 
<br/><br/><label>ISBN: </label>0872591689 
<br/><br/><label>LC Class. No.: </label>TK9956  / .Ar6 1990