| Author: | Jacob, P. L., 1806-1884 |
| Subject: | Z, Cryptography, Ciphers, Signs and symbols |
| Format: | Electronic text |
| Date issued: | 2013 |
| Language: | French |
| Publisher: | Project Gutenberg, |
| Rights: | Public domain in the USA. |
| Download link: | La Cryptographie, ou, l'art d'écrire en chiffres [electronic resource] / P. L. Jacob |