Gaines, Helen Fouch� <br/><br/>
Cryptanalysis :  a study of ciphers and their solution - (E-Book) 
 Elementary cryptanalysis. 
Helen Fouch� Gaines 
 - New York :  Dover,  cop. 1956 
 - 237 s. :  ill., tab. 
 - Dover books on chess and checkers ;  97 .
<br/><br/><label>ISBN: </label>0-486-20097-3 
<br/><br/><label>Subjects--Geographic Terms: </label><br/>E-Book
<br/><br/><label>Dewey Class. No.: </label>652.8