Perhaps you should try some spelling variations:
"international crises economic series" » "international crisis economic series", "international crimes economic series", "international cases economic series", "international crises economics series", "international crises economic services", "international crises economy series", "international crime economic series", "international prices economic series"
"national policy economic series" » "national poverty economic series", "national policy economics series", "national policy economic services", "national policy 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: (("national policy economic series") or ("international crises economic series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("national policy economic series") OR ("international crises economic series")).
• Removing quotes may allow a broader search: (( national policy economic series ) or ( international crises economic series )).
• Adding a wildcard symbol may retrieve word variants: (("national policy economic series") or ("international crises economic series"))*.