Perhaps you should try some spelling variations:
"international political economic security" » "international policy economic security", "international political economy security", "international ecological economics security"
"international energy economic services" » "international best economic services", "international energy ecological services", "international energy economic surveys", "international energy economic studies", "international energy economics services", "international energy economy 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 security") or ("international energy economic services"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("international political economic security") OR ("international energy economic services")).
• Removing quotes may allow a broader search: (( international political economic security ) or ( international energy economic services )).
• Adding a wildcard symbol may retrieve word variants: (("international political economic security") or ("international energy economic services"))*.