Perhaps you should try some spelling variations:
"world economic and financial systems." » "world economic and financial statements.", "world economic and financial sectors."
"world economic and financial studies." » "world economic and financial services."
"world economic and financial system." » "world economic and financial sector."

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: (((("world economic and financial systems.") or ("world economic and financial system."))) or ((((("world economy and financial strength.") or ("world economic and financial studies."))) or ("world economic and financial crisis."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (((("world economic and financial systems.") OR ("world economic and financial system."))) OR ((((("world economy and financial strength.") OR ("world economic and financial studies."))) OR ("world economic and financial crisis.")))).
• Removing quotes may allow a broader search: (((( world economic and financial systems. ) or ( world economic and financial system. ))) or ((((( world economy and financial strength. ) or ( world economic and financial studies. ))) or ( world economic and financial crisis. )))).
• Adding a wildcard symbol may retrieve word variants: (((("world economic and financial systems.") or ("world economic and financial system."))) or ((((("world economy and financial strength.") or ("world economic and financial studies."))) or ("world economic and financial crisis."))))*.