# pdfdol > Data Object Layer for PDF data ## Pages in this subsection - [pdfdol](pdfdol.html.md): Data Object Layers for PDF data. - [pdfdol.base](pdfdol.base.html.md): Base objects for pdfdol - [pdfdol.bundle](pdfdol.bundle.html.md): Bundle several PDFs into one, with a contents page, per-document headers and bookmarks. - [pdfdol.download](pdfdol.download.html.md): Download PDF articles from markdown-formatted text. - [pdfdol.tools](pdfdol.tools.html.md): | `add_css`(html_text[, css]) ... - [pdfdol.util](pdfdol.util.html.md): Utils for pdfdol ## Optional - [Top-level llms.txt](../llms.txt): Complete documentation index.