Perhaps you should try some spelling variations:
"international policy economic surveys" » "international poverty economic surveys", "international prices economic surveys", "national policy economic surveys", "international policy economic studies", "international policy economic systems"
"international political economics series" » "international political economic series", "international political economies series", "international political economy series"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("international policy economic surveys") or ("international political economics series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international policy economic surveys") OR ("international political economics series"))*.
• Removing quotes may allow a broader search: (( international policy economic surveys ) or ( international political economics series ))*.