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