# Sources and permissions > PGPRO 培训 --- LLMS index: [llms.txt](/en/llms.txt) --- ## Official sources - [English course catalog](https://postgrespro.com/community/courses) - [Russian course catalog](https://postgrespro.ru/education/courses) - [English material directory](https://edu.postgrespro.com/) - [Russian material directory](https://edu.postgrespro.ru/) The site uses the PDF text layer from checksum-fixed archives to create native Markdown. The original fixed-layout HTML remains available as page and link evidence. The importer is `scripts/extract_markdown.py`; extraction statistics are written to `sources/extraction-manifest.json`. ## Permission boundary The course copyright pages allow non-commercial use within their stated terms, require written permission for commercial use and prohibit modifying the course materials. This repository is currently a local organization, structured extraction and translation-preparation workspace. Translation, modification and redistribution permission must be confirmed before publishing a Chinese edition.