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Systematic Reviews: Step 4: Manage Citations

Created by Health Science Librarians

About Step 4: Manage Citations

It takes an average of 11 hours for a systematic review team to manage citations

In Step 4 you will use a citation manager to keep track of all the articles you have found through your literature search. This involves:

  1. Exporting all the search results.
  2. Uploading search results to your citation manager.
  3. Removing duplicate articles that were in more than one database.
  4. Moving articles from your citation manager to your systematic review software for screening.

This page has information about the different citation managers available at UNC. Librarians can recommend citation managers, help you troubleshoot if you run into problems, and provide instructions for using citation managers.

Click an item below to see how it applies to Step 4: Manage Citations.

For your PRISMA flow diagram, you will need to record the number of results from each database and remove duplicate citations, then report the number of duplicates removed. For information on how to document deduplication on your PRISMA flow diagram, visit our FAQ "How do I document duplicate removal on my PRISMA flow diagram?"


Covidence can automatically detect some duplicates if you import directly from the databases you search. You can also flag citations as duplicates in the screening process.

A librarian can advise you on citation management for your systematic review, including: 

  • Which citation manager to choose for a review 
  • How to export citations from a literature database to a citation manager
  • How to remove/combine duplicate citations
  • How to export citations from your citation manager for screening 



Select a tool for citation management

Several tools are available to manage citations during a systematic review. Citation management software can be complicated to use, and databases have different capabilities when it comes to exporting citations. Librarians have expertise in citation management and can ensure that citations are managed efficiently and appropriately.

Citation managers

Library staff can help you with the following citation management tools:

Which citation managers work best for systematic reviews?

When choosing a citation manager for a systematic review, consider factors like cost, format, storage capacity, and how it will perform for common systematic review tasks.

For example:

  • Sciwheel is user-friendly, but it automatically removes duplicate articles when you import, which can sometimes make it difficult to keep track of numbers for your PRISMA flow diagram.  Sciwheel cannot perform bulk uploads of PDFs to Covidence for full text screening and it is web-based, so you need an internet connection in order to use it.
  • EndNote Desktop is robust and allows you to customize deduplication and display settings, can automatically download some PDFs, and allows bulk uploads of PDFs to Covidence for full text screening.  EndNote is our only citation manager that you must purchase, but it is available at a discount through the Student Acquisition Ordering Portal if you are a student or through the BuyCarolina Marketplace in ConnectCarolina if you are faculty or staff.
  • Zotero merges duplicates throughout the library, which can sometimes make it difficult to keep track of numbers for your PRISMA flow diagram. The free version also limits you to a certain amount of storage, which may not be enough if you are conducting a large review or multiple reviews. Zotero can automatically download some PDFs and supports bulk uploads to Covidence for full text screening.
  • Mendeley can be used for systematic reviews, but HSL staff do not provide training or support for it.  Mendeley does support bulk PDF uploads to Covidence for full text screening.
  • Free tools such as Sciwheel, Zotero, or Mendeley may be a better option than a cost tool like EndNote if multiple members of your team need to access the library.

It is important to note that all these citation managers are compatible with Covidence for screening.  You can export a file of citations from any of these tools and import it into another tool if your review team members prefer different citation managers.  Your team can also choose not to use a citation manager at all, though citation managers can help make the review process easier.

Need a citation manager recommendation?Guide comparing features of Endnote, Zotero, and Sciwheel


Check out our guide Comparing Citation Managers which compares the features of EndNote, Zotero, and Sciwheel, or just Ask Us!


Zotero Sciwheel (formerly F1000Workspace)
HSL Online Guides EndNote Zotero Sciwheel (formerly F1000Workspace)
Classes at HSL EndNote Classes   Sciwheel Classes
Cost Under $100 through UNC-CH
Zotero is free Free through UNC-CH
Notes See EndNote Basic guide for further details on the free online version   Create an account. Select No, I'm a new user then select password.
How is it used? Computer
+ Web
+ Web
Major citation styles?
Annotation of PDFs
Locate full-text using UNC-CH subscriptions
Instructions for EndNote

Instructions for Zotero

Instructions for Sciwheel
Adds citation from a PDF
Sharing options X7 and above users have sharing options / email compressed libraries See group options here
Share unlimited projects and manuscripts
Free online storage X7 and above: unlimited 700+ papers
(more space can be purchased)
Word Processor Microsoft Word Microsoft Word
LibreOffice (all)
Microsoft Word
Google Docs
Manuscripts for Mac

Import and export articles

Importing articles to a citation manager

You'll need to export files from the databases into a citation manager of choice, remove the duplicate articles, and then export the remainder into Covidence.

Removing duplicate citations

Before screening your articles, you should first remove any duplicate listings of citations (deduplicate) in a citation manager such as EndNote, Sciwheel, or Zotero. Screening tools like Covidence can often help remove duplicates, but may not always work as expected.

View our Deduplication FAQs below for instructions on deduplicating in EndNote, Sciwheel, or Zotero.

Exporting your citations from a citation manager into Covidence

To import references from a citation manager into Covidence, you must create and export a document containing your citations and save it as an XML, CRS, or RIS text file. These files will have a .txt, .xml, or .ris file name.

Note: You can export from the databases into Covidence, but this is not recommended as Covidence misses some duplicate articles.