I just found this nice repository of old from from International Joint Conference on Artificial Intelligence. Lots of good stuff all the way from 1969.
One of my favorite findings was this paper from 1989 (If not mistake, the classic paper on velocity obstacles was published a decade later):
A Maneuvering-Board Approach to Path Planning with Moving Obstacles
Lou Tychonievich, David Zaret, John Mantegna, Robert Evans, Eric Muehle and Scott Martin
The year 1989 was like 20 years ago and yet we manage to produce games where NPCs have trouble avoiding walls and other kinds of minor things. So nice we have Google nowadays.
One quite important trick present in that '89 paper, that is missing from the Fiorini paper (IIRC) is the cone truncation. Applying the truncation helps a lot in many practical cases. Especially when trying to reach your final destination. Gladly it is well represented in Reciprocal n-body Collision Avoidance.