Perhaps you should try some spelling variations:
da literatura » la literatura, a literatura, de literatura
filosofia da » filosofia de, filosofia del, filosofia e
tests scale » tests stable, sets scale, tests safe
studies di » studies die, studies div, studies d

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 scale ((studies di) OR (studies ds)) filosofia da literatura".
• Adding a wildcard symbol may retrieve word variants: tests scale ((studies di) OR (studies ds)) filosofia da literatura*.