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

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