Perhaps you should try some spelling variations:
del literatura » de literatura, pela literatura, da literatura
der filosofia » de filosofia, e filosofia, di filosofia
sets scales » sets scaled, sets locales, sites scales
studien der » studie der, studenten der
sets scale » sets scaled, set scale, sets stable

You may be able to get more results by adjusting your search query.

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