Perhaps you should try some spelling variations:
"international border economic studies" » "international borders economic studies", "international order economic studies", "international bidders economic studies", "international border economic status", "international broader economic studies", "international worker economic studies", "international bolster economic studies"
"international policy economics series" » "international poverty economics series", "international prices economics series", "national policy economics series", "international policy economic series", "international politics economics series", "international politik 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 border economic studies") or ("international policy economics series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international border economic studies") OR ("international policy economics series"))*.
• Removing quotes may allow a broader search: (( international border economic studies ) or ( international policy economics series ))*.