Perhaps you should try some spelling variations:
"international brief economic studies" » "international relief economic studies", "international border economic studies", "international bridge economic studies", "international brief economic status", "international brief economic surveys", "international tariff economic studies", "international area economic studies"
"international drive economic studies" » "international river economic studies", "international rivers economic studies", "international bridge economic studies", "international drive economic status", "international drive economic surveys", "international trade economic studies", "international free economic studies", "international d'ivoire economic studies"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("international brief economic studies") OR ("international drive economic studies"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((\"international brief economic studies\") OR (\"international drive economic studies\"))".
• Removing quotes may allow a broader search: (( international brief economic studies ) OR ( international drive economic studies )).
• Adding a wildcard symbol may retrieve word variants: (("international brief economic studies") OR ("international drive economic studies"))*.