Handling duplicates
Find papers that are in your library more than once, merge them into one record, or keep them separate.
Overview
If you add papers from several places, such as PDFs, DOIs, Zotero and BibTeX files, the same paper can end up in your library twice. Paperguide finds these copies for you and lets you merge them, so each paper has one record with all its folders, tags and notes.
Prevent duplicates when you import
Every import in Add Papers has a Skip duplicates option, and it's on by default. With it on, papers that are already in your library aren't added again. In the import results these show as "Already in your library", or "Same paper selected twice" if the same paper appeared twice in one import.
See Add References for the import options.
Review duplicates
Open the review
When Paperguide finds duplicates, a note such as 3 duplicates found appears at the bottom of the Reference Manager sidebar. Click it to open Review duplicates.
Check how each group was matched
Each group shows the copies side by side. Matched by tells you why Paperguide thinks they're the same paper:
- DOI
- PMID
- PMCID
- arXiv
- ISBN
- Semantic Scholar
- Title + author + year
Merge the copies
Click Merge copies. Paperguide keeps one copy and combines the folders, tags and notes from every copy into it, so nothing is lost.
If more than one copy has a PDF, first choose the one to keep: under Pick a copy to keep, click Keep this on that copy, then click Merge copies.
Merge many groups at once
When several groups are ready to merge, click Merge all ready to merge them in one step. The button shows how many groups are ready, for example Merge all ready (5). Groups where you still need to pick a copy are left for you to review.
Keep papers separate
Sometimes two papers look alike but are really different, such as a conference paper and the later journal article. Click Keep separate on that group. The papers stay in your library as separate references and are hidden from the review. They only reappear if you import another paper that matches them.
To keep every remaining group as it is, click Keep all separate.
When you're done, click Back to library.