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 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"

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