While this is the first I've noticed it, it's possible that this "feature" was added as far back as the initial release of Bookends 10, possibly even before. I've checked all the papers I've written recently and the letters go back to at least May 2007. I'm pretty sure this is very bad! What can be done (other than editing them out by hand)?Borges, Jorge Luis. Collected fictions. Trans. Andrew Hurley. New York: Viking, 1998a.
———. El Aleph. Madrid: Alianza Editorial, 1995b.
———. Ficciones. Madrid: Alianza Editorial, 2004c.
———. Otras inquisiciones. Madrid: Alianza Editorial, 2003d.
(Interestingly, using the Bibliography Formatter menu item generates a perfect bibliography, without the added numbers)