Perhaps you should try some spelling variations:
"international ecological economic surveys" » "international economics economic surveys", "international economic economic surveys", "international economies economic surveys", "international ecological economics surveys"
"international political economic theories" » "international policy economic theories", "international political economy theories", "international ecological economics theories", "international political economic theory"

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