Perhaps you should try some spelling variations:
del litterature » de litterature, des litteratures, et litterature
studies der » studies ds, studies d, studies dn
bast fibre » basalt fibre, bast fibers, based fibre
studies de » studies die, studies doe, studies due

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: "bast fibre ((studies de) OR (studies der)) filosofia del litterature".
• Adding a wildcard symbol may retrieve word variants: bast fibre ((studies de) OR (studies der)) filosofia del litterature*.