Opening website external links in new window — published usability tests

In usability discussions about opening website external links in new windows, with regard to the argument of "keeping users on the site" there are occasionally references to usability studies which show that users are actually likely to leave the origin site instead of returning (thus defeating the purpose of opening the link in a new window).

But I can't find actual recent published studies on this, and I've searched extensively. Though Jakob Nielson is reputed to be a foremost expert, his recommendations are old and have no citations that I can find.

Does anyone know of credible, recent, published usability studies where users were disoriented by new windows and were more likely to not return to the origin site?

Update:

I understand there are accessibility issues, but as those matters are well-documented and backed up by the WCAG, I'm not in need of evidence supporting them.

This question is intentionally specific to the argument of "I want to keep users on my site" because it is the argument which -- due to lack of supporting evidence -- I can't effectively counter in discussions with the client.

Update:

Found this 2006 PhD thesis on user browsing behavior. Haven't fully deciphered it, but the thesis does claim that new windows / tabs increase the cognitive burden on users.