Perhaps you should try some spelling variations:
"international policy economy series" » "international poverty economy series", "international prices economy series", "national policy economy series", "international policy economic series", "international polish economy series", "international politics economy series", "international policy economics series"
"international energy economic series" » "international energy economics series", "international energy economy series", "international ecology economic series", "international energy economic services", "international energy economic theories"

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 economy series") OR ("international energy economic series"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international policy economy series\") OR (\"international energy economic series\"))".
• Removing quotes may allow a broader search: (( international policy economy series ) OR ( international energy economic series )).
• Adding a wildcard symbol may retrieve word variants: (("international policy economy series") OR ("international energy economic series"))*.