Reference management software: EndNote

Remove duplicates

Select References → Find duplicates in EndNote. EndNote will now display duplicates side by side, and you can compare them and select the one you wish to keep in your library. The older (first entered) reference will always appear in the left column.

Instructional video: Find Duplicates.

When you save one of the duplicates, the other is deleted. If the deleted version was in a group without its duplicate, it disappears from the group.