Perhaps you should try some spelling variations:
stems studies » stem studies, systems studies, atoms studies
la literatura » la litterature, a literature
di filosofia » la filosofia, e filosofia
filosofia la » filosofia da, filosofia le, filosofica da
items die » items der, items des

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: test ((stems studies) OR (items die)) di filosofia la literatura.
• Adding a wildcard symbol may retrieve word variants: test ((stems studies) or (items die)) di filosofia la literatura*.