Perhaps you should try some spelling variations:
del litterature » de litterature, des litteratures, et litterature
fishes studies » fish studies, fisheries studies, figures studies
files studies » films studies, film studies, filho studies
div filosofia » di filosofia, de filosofia, da filosofia

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: "test ((files studies) OR (fishes studies)) div filosofia del litterature".
• Adding a wildcard symbol may retrieve word variants: test ((files studies) OR (fishes studies)) div filosofia del litterature*.