> For the complete documentation index, see [llms.txt](https://helpcenter.paperguide.ai/llms.txt). > Use it to discover all available pages before exploring further. # Add References Add references by DOI, URL, BibTeX, RIS, or PDF with auto-citation. ## What is Add References? Add References is how you build your reference library in Paperguide. You can add references in multiple ways by DOI, URL, ISBN, arXiv ID, BibTeX, RIS, or PDF upload. The AI automatically extracts metadata and generates a formatted citation for each reference you add. ## Auto-cite Auto-cite is the fastest way to add a reference. Paste an identifier and Paperguide fetches the metadata automatically. Select from DOI, URL, ISBN, or arXiv ID depending on what you have. Enter the DOI, URL, ISBN, or arXiv ID. For example, use `10.1234/example` for a DOI or `2301.00001` for an arXiv ID. Paperguide retrieves the title, authors, year, journal, abstract, and other available metadata from external sources. The reference appears in your library with a formatted citation. Review the metadata and correct any fields that need adjustment. Auto-cite works best with DOIs and direct publisher URLs. These usually return the most complete and reliable metadata. ## PDF upload Upload PDF files directly from your device when you already have the paper file. Paperguide reads the PDF and creates a reference from the metadata it can identify. Drag and drop one or more PDF files, or browse your device to select them. Paperguide scans the PDF to identify the title, authors, year, DOI, and other available metadata. Each uploaded PDF becomes a reference in your library with the PDF attached. The file is also available for search and AI-assisted workflows inside your workspace. ## BibTeX import Import BibTeX when you are moving references from a LaTeX workflow or another reference manager. Each BibTeX entry becomes a separate reference in your library. Open the import options and choose BibTeX. Paste BibTeX entries into the text field or upload a `.bib` file from your device. Paperguide parses each entry and creates a separate reference with its metadata fields. ## RIS import Import RIS when you export references from tools that support RIS format. This is a common way to bring in references from citation databases and reference managers. Open the import options and choose RIS. Paste RIS entries directly or upload a `.ris` file from your device. Paperguide parses each RIS entry and creates a separate reference in your library. ## Batch URL import Paste multiple URLs at once when you need to add several papers in one pass. Paperguide processes each URL, extracts the available metadata, and creates a reference for each source it can identify. Batch URL import helps when you are collecting papers from publisher sites, preprint servers, or reading lists. If a URL does not return enough metadata, review the created reference and fill in any missing details. ## Manual entry Enter reference details yourself when auto-cite cannot find a match or when the source does not have a usable online record. Add the title, authors, year, journal, DOI, and any other fields you need, then save the reference to your library. Manual entry is most useful for: - Offline documents - Incomplete web sources - Older papers with inconsistent metadata - Internal reports, white papers, or unpublished material ## Next steps