How toautomatically transfer references fgrom paper to library

I am sharing a paper with another colleague.  How do i automaically have her references (that I do not have) added to my endnote library when I am adding text and citations at my end . 

on the endnote ribbon in word, there is a dropdown option to export to endnote.  I would export to a new library and import that library into your main library with discard duplicates on, so you only retrieve the new references.