HARD sc Publishing Company is committed to the long-term preservation of its scholarly content. To ensure that all published articles remain accessible for future generations, we employ the following strategy:

• National Depository (Legal Deposit): In accordance with Polish law and as a condition of our ISSN registration, all issues of PJOES and PJOESPEAI are deposited with the National Library of Poland (Biblioteka Narodowa). This ensures that the journal’s content is preserved in the national archival system.
• Internal Redundancy: HARD sc Publishing Company maintains full digital backups of all published materials on secure, redundant servers to protect against data loss.
• Self-Archiving: Authors are encouraged to self-archive the published version of their articles in their institutional repositories or on personal websites (Green Open Access) to further ensure the availability of their research.
• International Third-Party Preservation: We are pleased to announce that our full archive will be deposited into the Portico “dark archive” to provide a secondary, independent layer of global digital sustainability.