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 policy economic theories") or ("international economics economics series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international policy economic theories") OR ("international economics economics series")).
• Removing quotes may allow a broader search: (( international policy economic theories ) or ( international economics economics series )).
• Adding a wildcard symbol may retrieve word variants: (("international policy economic theories") or ("international economics economics series"))*.