Perhaps you should try some spelling variations:
"international economics economic theories" » "international economics econometric theories", "international economics economic theory", "international economics economics series"
"international prices economy series" » "international prices economic series", "international driven economy series", "international rich economy series", "international prices economics 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 economics economic theories") or ("international prices economy series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international economics economic theories") OR ("international prices economy series"))*.
• Removing quotes may allow a broader search: (( international economics economic theories ) or ( international prices economy series ))*.