1. M.E. Bailey: “Comet craters versus asteroid craters”, these proceedings.
2. Where do the Apollo objects come from?;Wetherill;Icarus,1988
3. Project SPACEGUARD: Dynamics of planet-crossing asteroids;Milani,1989
4. Evolution of comets into asteroids;Weissman,1989
5. Asteroids: The big picture;Bell,1989