Well, I've been searching high and low. There might be some stuff hidden at the NTU, perhaps in Norwegian. All of the leading folks at Fast are recruited there. There is some odds and ends, in conference papers etc, but AFAIK nothing like the famous papers cited in regard to Google. There is some stuff on the Enterprise search at Fast, for some of it you might use Wayback. Basically the processes between enterprise and websearch should be the same. What I've seen there was not directly related to ranking.