The reason is that Kate Elliott didn't collaborate with Andre Norton on The Burning Stone or any other book. In preparing bibliographies for this site I know that some of our moderators consult Fantastic Fiction, which in many ways is a great source, but given to occasional inaccuracies. Since lots of other sites get their information from Fantastic Fiction, the mistakes get repeated again and again -- people think they are seeing a fact verified by more than one source, they naturally assume that the information is good, but it all traces back to the same place.
I'm surprised that Kate/Alis didn't catch the mistake when she looked at her bibliography here -- also surprised that I didn't catch it -- but I do know that it is a mistake. When Ms. Norton died, I came across a reference to this same supposed collaboration and wrote to Alis to ask her about it (I've known her since the late 80's and felt sure I would have heard from her about anything as exciting as working on a project with Andre Norton). She confirmed what I already knew, that her only collaboration ever was with Melanie Rawn and Jennifer Roberson for The Golden Key.
