Perhaps you should try some spelling variations:
symposium sieds » symposium series, symposium sas, symposium sss
symposion des » symposions des, symposion der, symposion uber
das symposium » bacus symposium, texas 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: (( das symposion des ) OR ( das symposium sieds )).
• Adding a wildcard symbol may retrieve word variants: (( das symposion des ) or ( das symposium sieds ))*.