Perhaps you should try some spelling variations:
la litterature » a literature
filosofia la » filosofia da, filosofia le, filosofica da
testi della » test della, testa della, testi delle
studien dde » studien die, studien der, studien des
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: testi della ((studien dd) OR (studien dde)) filosofia la litterature.
• Adding a wildcard symbol may retrieve word variants: testi della ((studien dd) or (studien dde)) filosofia la litterature*.