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

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