Perhaps you should try some spelling variations:
"international aid economic services" » "international airshow economic services", "international airport economic services", "international aid economics series", "international aid ecological services", "international aid economic studies", "international rapid economic services", "international aids economics services", "international avoid economic services"
"international prices economic series" » "international crises economic series", "international prices econometric series", "international services economic series", "international prices economics series", "international prices economy series", "international prices economic theories"

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