Perhaps you should try some spelling variations:
"international openness economy series" » "international roughness economy series", "international business economy series", "international agencies economy series", "international open economy series"
"international energy economic series" » "international best economic series", "international energy economics series", "international energy economy series", "international energy economic services", "international energy economic theories", "international energy economic surveys"

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