Perhaps you should try some spelling variations:
central banks » central bank
jeong hyeok » jeong dahyeon
die banken » der banken
minh jeong » min jeong, minh cong
zhang hai » zhang dai, shang hai, zhang han
yan yuan » yan guan, fang yuan, nan yan
yan yan » nan yan, yang yang, wang yan

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((yan yan) OR (yan yuan)) zhang hai ((central banks) OR (die banken)) minh jeong hyeok ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((yan yan) OR (yan yuan)) zhang hai ((central banks) or (die banken)) minh jeong hyeok ;~".
• Adding a wildcard symbol may retrieve word variants: ((yan yan) OR (yan yuan)) zhang hai ((central banks) or (die banken)) minh jeong hyeok ;*.