Perhaps you should try some spelling variations:
"international political economy services" » "international policy economy services", "international political economic services", "international political economy series", "international political recovery services"
"national poverty economic series" » "national property economic series", "national forestry economic series", "national policy economic series", "national poverty economics series", "national poverty economic services", "national poverty economy series"

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