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 surveys"
"national poverty economic studies" » "national property economic studies", "national forestry economic studies", "national policy economic studies", "national poverty economic status"

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