I just finished reading through almost all of the stories in George R. R. Martin's The Thousand Worlds universe. These stories are not advertised as being part of the same universe, so one has to rely on hearsay, or the author's word in order to locate them. Other than that, the only way to tell is to read them and look for clues in the text.
Wikipedia says that the story With Morning Comes Mistfall takes place in this universe as well. The problem is that Wikipedia cites a blog post by the author in which he makes no such claims (or any mention to that particular story whatsoever).
Additionally, the actual text of the story didn't ring any bells to me — it has no reference to any The Thousand Worlds-specific alien races or locations that I recognized. I figure if it does take place in this world, it's very early, before the major events that shaped the universe (such as the Double War).
Is there any evidence that this story does in fact take place in that universe?