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 ecological services", "international political economic studies", "international political economic survey"
"national poverty economic surveys" » "national policy economic surveys", "national energy economic surveys", "national poverty economic survey"

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