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"
"acs symposium sieds" » "acs symposium sas", "acs symposium sss", "acs symposium semi", "bacus symposium sieds", "lakes symposium sieds", "games symposium sieds"
"backs symposium irs" » "bacus symposium irs", "spaces symposium irs", "lakes symposium irs", "backs symposium iv", "backs symposium ii", "backs symposium iii", "backs symposium ivrs", "backs symposium isvcrs"
"acs symposium i" » "bacus symposium i", "lakes symposium i", "games symposium i", "acs 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: (((("backs symposium irs") OR ("acs symposium i"))) OR ((("acs symposium sieds") OR ("das symposium series")))).
• Removing quotes may allow a broader search: (((( backs symposium irs ) or ( acs symposium i ))) or ((( acs symposium sieds ) or ( das symposium series )))).
• Adding a wildcard symbol may retrieve word variants: (((("backs symposium irs") or ("acs symposium i"))) or ((("acs symposium sieds") or ("das symposium series"))))*.