Perhaps you should try some spelling variations:
"international poverty economic surveys" » "national poverty economic surveys", "international property economic surveys", "international forestry economic surveys", "international policy economic surveys", "international poverty economic studies", "international poverty economic systems"
"international service economy series" » "international price economy series", "international series economy series", "international rice economy series", "international service economics 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 surveys") or ("international service economy series"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international poverty economic surveys") OR ("international service economy series")).
• Removing quotes may allow a broader search: (( international poverty economic surveys ) or ( international service economy series )).
• Adding a wildcard symbol may retrieve word variants: (("international poverty economic surveys") or ("international service economy series"))*.