Perhaps you should try some spelling variations:
"world economic and financial series." » "world economic and financial services.", "world economic and financial service.", "world economic and financial studies."
"world economy and financial series." » "world economy and financial services.", "world economy and financial service.", "world economy and financial studies."
"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 system.") or ((("world economic and financial series.") or ("world economy and financial series."))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("world economic and financial system.") OR ((("world economic and financial series.") OR ("world economy and financial series.")))).
• Removing quotes may allow a broader search: (( world economic and financial system. ) or ((( world economic and financial series. ) or ( world economy and financial series. )))).
• Adding a wildcard symbol may retrieve word variants: (("world economic and financial system.") or ((("world economic and financial series.") or ("world economy and financial series."))))*.