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 » international policy
"International political economy studies" » "International political economic studies", "International political economy series"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("International political economy studies") OR ("international ecological economics studies"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"International political economy studies\") OR (\"international ecological economics studies\"))".
• Removing quotes may allow a broader search: (( International political economy studies ) OR ( international ecological economics studies )).
• Adding a wildcard symbol may retrieve word variants: (("International political economy studies") OR ("international ecological economics studies"))*.