Perhaps you should try some spelling variations:
"international african economic series" » "international africa economic series", "international american economic series", "international afghan economic series", "international taiwan economic series", "international african economics series", "international african economy series", "international african economic theories"
"national policy economic services" » "national policy economics series", "national policy ecological services", "national policy economic studies", "national poverty economic services"

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