Friedman, William F <br/><br/>
The Index of Coincidence and its Applications in Cryptanalysis  

 - California  Aegean Park Press  c1987 
 - 95,p:  ill:  26,cm, 
<br/><br/><label>ISBN: </label>0894121375  Available 
<br/><br/><label>Subjects--Topical Terms: </label><br/>NSA, Cryptography, National Security Agency,
<br/><br/><label>Dewey Class. No.: </label>005.54 FRI