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

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