Perhaps you should try some spelling variations:
"international policy economic theories" » "international poverty economic theories", "international prices economic theories", "national policy economic theories", "international policy economic theory"
"international economics economics series" » "international economics economic series", "international economics econometric series", "international ecological economics series"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("international economics economics series") OR ("international policy economic theories"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international economics economics series\") OR (\"international policy economic theories\"))*".
• Removing quotes may allow a broader search: (( international economics economics series ) OR ( international policy economic theories ))*.