Perhaps you should try some spelling variations:
de litterature » la litterature, et litterature
heart student » health student, smart student, retort student
de literatura » la literatura, y literatura, a literatura
tests heart » tests heat, tests part, less heart

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 heart student _ filosofia ((de literatura) OR (de litterature))".
• Adding a wildcard symbol may retrieve word variants: tests heart student _ filosofia ((de literatura) OR (de litterature))*.