Perhaps you should try some spelling variations:
"national poverty economic series" » "national property economic series", "national forestry economic series", "national policy economic series", "national poverty economics series", "national poverty economic services", "national poverty economy series"
"international prices economic series" » "international prices economics series", "international prices economic services", "international prices economy series", "international crises economic series", "international prices econometric series", "international services economic series"

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