Perhaps you should try some spelling variations:
"international policy economic surveys" » "international poverty economic surveys", "international prices economic surveys", "national policy economic surveys", "international policy economic studies"
"International political economic systems" » "International political economy systems", "International ecological economics systems", "International political economic sectors", "International political economic status"

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