Perhaps you should try some spelling variations:
"international ecological economic studies" » "international economics economic studies", "international economic economic studies", "international political economic studies", "international ecological economics studies", "international ecological economic status", "international ecological economic surveys"
"international prices economic theories" » "international best economic theories", "international banks economic theories", "international prices economic theory", "international crisis economic theories", "international brief economic theories", "international africa's economic theories"

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