Perhaps you should try some spelling variations:
la literatura » la litterature
e filosofica » e filosofia, e filosofiche, a filosofia
de studie » die studie, e studie, mode studie
de studio » de estudio, _ studio, a studio

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 ((de studie) OR (de studio)) e filosofica ((y literatura) OR (((la literatura) OR (a literature)))).
• The words AND, OR and NOT may confuse the search; try adding quotes: "test ((de studie) or (de studio)) e filosofica ((y literatura) or (((la literatura) OR (a literature))))".
• Adding a wildcard symbol may retrieve word variants: test ((de studie) or (de studio)) e filosofica ((y literatura) or (((la literatura) OR (a literature))))*.