Endnote can import references from most databases and in many different formats.
First, the references must be exported from the databases. After this, they must be imported/opened by Endnote.
It is best to choose the RIS or EndNote formats.
Instructions for importing references:
If the file format is unknown, you will be greeted by the following menu:
Click on "More apps"
Select Endnote and tick that you always want to use this program.
Open and import the references.
The first time Endnote must import references in a new file format, your Mac must learn that Endnote must open this type of file. This is done via Finder:
Click with 2 fingers (or Ctr + click) on the file you want to open and Finder will open the following menu
Select "Choose Application".
Select "Always open with" so that your Mac remembers that the file format and Endnote belong together.
Open and import the references.
If you are asked to open a library, you will find "My Endnote Library" in the folder "Documents.