Perhaps you should try some spelling variations:
"international political economic surveys" » "international policy economic surveys", "international political economy surveys", "international ecological economics surveys"
"international energy ecological services" » "international best ecological services", "international energy hydrological services", "international energy clinical services", "international energy meteorological services", "international energy psychological services", "international energy economics services", "international energy economic services"

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("international political economic surveys") or ("international energy ecological services"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international political economic surveys") OR ("international energy ecological services"))*.
• Removing quotes may allow a broader search: (( international political economic surveys ) or ( international energy ecological services ))*.