Perhaps you should try some spelling variations:
"international prices economic series" » "international best economic series", "international banks economic series", "international crisis economic series", "international brief economic series", "international africa's economic series", "international prices economic services", "international prices economic theories", "international prices economic surveys"
"national poverty economic studies" » "national policy economic studies", "national energy economic studies", "national poverty economic status", "national poverty economic surveys"

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

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