Perhaps you should try some spelling variations:
de literatura » de litterature, y literatura, a literatura
la literatura » la litterature, a literature
d studie » d studies, 4d studie, 3 studie
1 studie » 1 studies, 1 studien, 3 studie

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 ((d studie) OR (1 studie)) _ filosofia ((de literatura) OR (la literatura)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "test ((d studie) OR (1 studie)) _ filosofia ((de literatura) or (la literatura))".
• Adding a wildcard symbol may retrieve word variants: test ((d studie) OR (1 studie)) _ filosofia ((de literatura) or (la literatura))*.