Perhaps you should try some spelling variations:
del literature » model literature, abel literature, fuel literature
studies lia » studies lca, studies li, studies lit
best scale » bast scale, rest scale, burst scale
studies la » studies lab, studies lca, studies l2

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: "best scale ((studies la) OR (studies lia)) filosofia del literature".
• Adding a wildcard symbol may retrieve word variants: best scale ((studies la) OR (studies lia)) filosofia del literature*.