Perhaps you should try some spelling variations:
tests stable » tests table, sets stable, test table
a literatura » la literatura, a literature, a literatur
y literatura » la literatura
tests scale » sets scale, tests safe, tests shall
e filosofia » la filosofia
student e » student _, student a, student 1

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: ((tests scale) OR (tests stable)) student e filosofia ((a literatura) OR (y literatura)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tests scale) OR (tests stable)) student e filosofia ((a literatura) or (y literatura))".
• Adding a wildcard symbol may retrieve word variants: ((tests scale) OR (tests stable)) student e filosofia ((a literatura) or (y literatura))*.