Perhaps you should try some spelling variations:
"international political economic survey" » "international policy economic survey", "international political economy survey", "international ecological economics survey", "international political economic surveys", "international political economic security", "international political economic studies"
"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"

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 political economic survey") or ("international energy ecological services"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international political economic survey") OR ("international energy ecological services")).
• Removing quotes may allow a broader search: (( international political economic survey ) or ( international energy ecological services )).
• Adding a wildcard symbol may retrieve word variants: (("international political economic survey") or ("international energy ecological services"))*.