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

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• Performing a fuzzy search may retrieve terms with similar spellings: (("international political economic studies") OR ("international ecological economics theories"))~.
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• Removing quotes may allow a broader search: (( international political economic studies ) OR ( international ecological economics theories )).
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