Perhaps you should try some spelling variations:
conference amast » conference acisp, conference acns, conference alt
conference adma » conference adbis, conference a, conference acns
rabies 2001 » navies 2001
rabies 20 » rabies 10, rabies 2, rabies 23

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: world ((conference amast) OR (conference adma)) ((rabies 2001) OR (rabies 20)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "world ((conference amast) OR (conference adma)) ((rabies 2001) or (rabies 20))".
• Adding a wildcard symbol may retrieve word variants: world ((conference amast) OR (conference adma)) ((rabies 2001) or (rabies 20))*.