Perhaps you should try some spelling variations:
en literatura » e literatura, pena literatura, en litterature
e filosofia » la filosofia
y filosofia » a filosofia, la filosofia, di filosofia
texten das » texten des, texten der, text das
texto das » text das, texto mas, texto de

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: ((texto das) OR (texten das)) studium ((e filosofia) OR (y filosofia)) en literatura.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((texto das) OR (texten das)) studium ((e filosofia) or (y filosofia)) en literatura".
• Adding a wildcard symbol may retrieve word variants: ((texto das) OR (texten das)) studium ((e filosofia) or (y filosofia)) en literatura*.