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 economic surveys" » "international political economy surveys", "international ecological economics surveys", "international political economic studies", "international political economic systems"

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