Perhaps you should try some spelling variations:
"international policy economic series" » "international poverty economic series", "international prices economic series", "national policy economic series", "international policy economics series", "international policy economic services", "international policy economy series"
"international political economy theories" » "international political economic theories", "international political economics theories", "international political 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: (("international policy economic series") OR ("international political economy theories"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international policy economic series\") OR (\"international political economy theories\"))".
• Removing quotes may allow a broader search: (( international policy economic series ) OR ( international political economy theories )).
• Adding a wildcard symbol may retrieve word variants: (("international policy economic series") OR ("international political economy theories"))*.