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 survey" » "national poverty economic survey", "national policy economic surveys", "national policy economic security", "national policy economic studies"

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