To export several citations at a time out of Discovery and into your Mendeley Reference Manager' software, follow these steps:
Step 1: Do one or more searches of Discovery and select the citations you want to keep.
Step 2: When you have finished searching, open your list of chosen citations by clicking on 'My Items' in the top right corner.
Step 2: At this point you can review your list and un-select the citations you no longer want.
Step 3: Click on the 'Cite' button.
Step 4: Click on 'Export to RIS'
Step 5: Open your Mendeley Reference Manager software and import the file in RIS format.