Perhaps you should try some spelling variations:
"das symposium series" » "das symposium semi", "das symposium sas", "das symposium sss", "das symposion series", "bacus symposium series", "texas symposium series"
"das symposium sieds" » "das symposium sas", "das symposium sss", "das symposium semi", "das symposion sieds", "bacus symposium sieds", "texas symposium sieds"
"acs symposium irs" » "bacus symposium irs", "lakes symposium irs", "games symposium irs", "acs symposium i", "acs symposium ii", "acs symposium iii"
"acs symposium iv" » "bacus symposium iv", "lakes symposium iv", "games symposium iv", "acs symposium isvc"

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: (((("acs symposium irs") OR ("acs symposium iv"))) OR ((("das symposium sieds") OR ("das symposium series")))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"acs symposium irs\") or (\"acs symposium iv\"))) or (((\"das symposium sieds\") OR (\"das symposium series\"))))".
• Removing quotes may allow a broader search: (((( acs symposium irs ) or ( acs symposium iv ))) or ((( das symposium sieds ) OR ( das symposium series )))).
• Adding a wildcard symbol may retrieve word variants: (((("acs symposium irs") or ("acs symposium iv"))) or ((("das symposium sieds") OR ("das symposium series"))))*.