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 political economy surveys" » "international political economic surveys", "international political economy series", "international political economic survey"

Try widening your search to All Fields.

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