Perhaps you should try some spelling variations:
"international poverty economic theories" » "national poverty economic theories", "international poverty economic theory", "international poverty economics series", "international property economic theories", "international forestry economic theories", "international policy economic theories"
"international roman economy series" » "international human economy series", "international road economy series", "international roaming economy series", "international roman economics series", "international command economy series", "international german economy series"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("international poverty economic theories") or ("international roman economy series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international poverty economic theories") OR ("international roman economy series")).
• Removing quotes may allow a broader search: (( international poverty economic theories ) or ( international roman economy series )).
• Adding a wildcard symbol may retrieve word variants: (("international poverty economic theories") or ("international roman economy series"))*.