Answered By: Kathryn Devine
Last Updated: Aug 19, 2022     Views: 37

If you have exported your search results from a database into Zotero (reference management software) or an Excel spreadsheet, you will probably want to check whether you have any duplicate records, particularly if you are completing a systematic literature review.

In Zotero:

  • Click "duplicate items" under "My Library" on the left hand side of your Zotero screen
  • Zotero will identify and group the duplicate records together
  • If you are happy they are genuine duplicates, click "merge" on the right hand side of the screen

Zotero library menu with duplicate items selected

Screenshot of Zotero duplicate items; merge items button highlighted

In Excel:

  • Open the spreadsheet containing your search results
  • Select the relevant data in your spreadsheet
  • Click the "data" tab at the top of the screen
  • Under "data tools", click "remove duplicates"
  • Select which column(s) you want Excel to check - usually the article title
  • Click "OK"

Excel remove duplicates screenshot

Excel screenshot showing column values selected to remove duplicates

Excel will remove exact duplicates. You will see a dialog box informed you how many duplicates have been removed, and how many unique records remain.