For each set of search results, you will want to save all citations of interest. Depending on the database, you can then email, and/or save, and/or export selected citations. Exporting results in BibTeX, MEDLINE, RIS or XML files will allow you to then import selections into a citation management tool.

If you are gathering citations from multiple databases, you will need to de-duplicate results once you have imported everything. This process will vary depending on the citation management tool you are using.

• EndNote
  From the menu bar select “Library” → “Find Duplicates”. Use “Keep This Record” to select the records to keep. Use "Skip" to keep both records.
• Zotero
  Click on the "Duplicate Items" collection in your library. You can resolve duplicates by merging the files. 
• Mendeley
  Select the folder of interest. Go to theTools menu and select "Check for Duplicates". Select the details that you would like to keep from each document. Click merge to create one entry containing the complete document details.
• Covidence
  Automatically de-duplicates your results. Click here for more information about Covidence de-duplication.