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