Add references from the summary interface of your review (Review Summary).
Once the import is complete, an indication of the number of duplicates will appear. It will be possible to check them one by one by clicking on the link.
A record of the number of duplicates removed will remain (x total duplicates removed).
Duplicate management is done in Covidence or in your bibliographic management software like EndNote or Zotero.
Note that no tool manages duplicates with 100% efficiency.
Advantages of managing duplicates in Covidence (1) :
(1) Utiliser Covidence des bibliothèques de l'Université Laval, s. d.