Perhaps you should try some spelling variations:
la literatura » la litterature, a literature
a literatura » a literature, y literatura, a literatur
auf studie » auf studium, auf stufe, hf studie
tests auf » test auf, tests a

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: "tests auf studie _ filosofia ((a literatura) OR (la literatura))".
• Adding a wildcard symbol may retrieve word variants: tests auf studie _ filosofia ((a literatura) OR (la literatura))*.