1995 profile in Village Voice by Aaron Barnhart: http://web.archive.org/web/19970521233803/http://www.echonyc.com/~barnhart/donz5.html
2015 Q&A by Jeff Zuk: http://byeletterman.tumblr.com/post/117791876292/a-chat-with-don-giller-david-yoder
2017 profile in New York Times by Jason Zinoman: https://www.nytimes.com/2017/04/06/fashion/mens-style/david-letterman-late-show-don-giller.html
Update to the Times profile: The collection is now at 100%.
New update: All of Late Night with David Letterman has now been digitized. Here's the back-story: