Perhaps you should try some spelling variations:
filosofia de » filosofia del
sets scales » sets scaled, sets locales, sites scales
filosofia e » filosofia del
sets scale » sets scaled, set scale, sets stable
studien dd » studies dd, studien der, studien die

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: ((sets scale) OR (sets scales)) studien dd ((filosofia e) OR (filosofia de)) literatura.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((sets scale) or (sets scales)) studien dd ((filosofia e) OR (filosofia de)) literatura".
• Adding a wildcard symbol may retrieve word variants: ((sets scale) or (sets scales)) studien dd ((filosofia e) OR (filosofia de)) literatura*.