Perhaps you should try some spelling variations:
"international ecological economics studies" » "international technological economics studies", "international psychological economics studies", "international economics economics studies", "international ecological economic studies", "international ecological economics series", "international ecological economics study"
"international political economy theories" » "international policy economy theories", "international political economic theories", "international political economics theories", "international political economy series"

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