Perhaps you should try some spelling variations:
"international political economics series" » "international policy economics series", "international political economic series", "international political economies series", "international political economy series"
"international prices economic services" » "international prices ecological services", "international prices economic studies", "international prices economic surveys", "international crises economic services", "international prices econometric services", "international services economic services"

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