Perhaps you should try some spelling variations:
del literatura » de literatura, pela literatura, da literatura
test scale » tests scale, best scale, treat scale
rest scale » best scale, rust scale, great scale
studies la » studies lab, studies lca, studies lia

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: "((test scale) OR (rest scale)) studies la filosofia del literatura*".