Perhaps you should try some spelling variations:
del literatura » pela literatura, da literatura, e literatura
de literatura » de litterature, la literatura, y literatura
rest scale » best scale, great scale, tests scale
rust scale » trust scale, just scale, robust scale
study la » study law, study lay, study lca

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: ((rest scale) OR (rust scale)) study la filosofia ((del literatura) OR (de literatura)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((rest scale) or (rust scale)) study la filosofia ((del literatura) OR (de literatura))".
• Adding a wildcard symbol may retrieve word variants: ((rest scale) or (rust scale)) study la filosofia ((del literatura) OR (de literatura))*.