Perhaps you should try some spelling variations:
"international policy economic series" » "international poverty economic series", "national policy economic series", "international policy economics series", "international policy economic services", "international policy economy series"
"international prices economy theories" » "international prices economic theories", "international prices economics theories", "international prices economy series", "international driven economy theories", "international rich economy theories"

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