Perhaps you should try some spelling variations:
"aaas symposium series" » "aaas symposium sas", "aaas symposium sss", "aaas symposium spire", "das symposium series", "acs symposium series", "cas symposium series"
"abacus symposium semi" » "bacus symposium semi", "acs symposium semi", "spaces symposium semi", "abacus symposium sas", "abacus symposium sss", "abacus symposium sagt"

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 series") OR ("abacus symposium semi")).
• Removing quotes may allow a broader search: (( aaas symposium series ) or ( abacus symposium semi )).
• Adding a wildcard symbol may retrieve word variants: (("aaas symposium series") or ("abacus symposium semi"))*.