Perhaps you should try some spelling variations:
"international political economic series" » "international policy economic series", "international political economy series", "international ecological economics series", "international political economic services", "international political economic theories", "international political economic surveys"
"international economics ecological studies" » "international economics technological studies", "international economics economic studies", "international economics economics studies", "international economics ecological services", "international economics clinical 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 political economic series") or ("international economics ecological studies"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international political economic series") OR ("international economics ecological studies")).
• Removing quotes may allow a broader search: (( international political economic series ) or ( international economics ecological studies )).
• Adding a wildcard symbol may retrieve word variants: (("international political economic series") or ("international economics ecological studies"))*.