Perhaps you should try some spelling variations:
aaas symposium » das symposium, cas symposium, iass symposium
gras symposium » brass symposium, das symposium, cas symposium
acs symposium » bacus symposium, das symposium, lakes symposium

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: ((((aaas symposium) OR (gras symposium))) OR (acs symposium)) (sans OR sams).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((aaas symposium) OR (gras symposium))) or (acs symposium)) (sans or sams)".
• Adding a wildcard symbol may retrieve word variants: ((((aaas symposium) OR (gras symposium))) or (acs symposium)) (sans or sams)*.