Perhaps you should try some spelling variations:
"international policy economic studies" » "international poverty economic studies", "national policy economic studies", "international policy economic status"
"international prices econometric services" » "international prices economic services", "international prices obstetric services", "international prices economic series", "international crises econometric services", "international rates econometric services", "international policy econometric services"

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