http://www.gutenberg.org/ebooks/subject/7600.opds 2024-11-08T07:14:27Z Books about Ciphers (sorted by popularity) Free eBooks since 1971. Project Gutenberg https://www.gutenberg.org webmaster@gutenberg.org https://www.gutenberg.org/gutenberg/favicon.ico 25 1 2024-11-08T07:14:27Z https://sendtokindle.compellingsciencefiction.com/ebooks/subject/7600.opds?sort_order=title Sort Alphabetically by Title 2024-11-08T07:14:27Z https://sendtokindle.compellingsciencefiction.com/ebooks/subject/7600.opds?sort_order=release_date Sort by Release Date 2024-11-08T07:14:27Z https://sendtokindle.compellingsciencefiction.com/ebooks/26839.opds Mathematical Recreations and Essays W. W. Rouse Ball 2024-11-08T07:14:27Z https://sendtokindle.compellingsciencefiction.com/ebooks/48871.opds Manual for the Solution of Military Ciphers Parker Hitt 2024-11-08T07:14:27Z https://sendtokindle.compellingsciencefiction.com/ebooks/42297.opds La Cryptographie, ou, l'art d'écrire en chiffres (French) P. L. Jacob