Perhaps you should try some spelling variations:
"international poppy economics series" » "international policy economics series", "international ports economics series", "international power economics series", "international poppy economy series", "international apply economics series"
"international prices economic surveys" » "international prices economic studies", "international prices economic systems", "international crises economic surveys", "international prices econometric surveys", "international services economic surveys"

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