Perhaps you should try some spelling variations:
cheng yang » cheng zhang, chen wang, cheng han
chen yang » chen rong
john wong » john song, john bonn
yan yang » yang yang, yao yang, dan yang
wong sau » wong sam, wong siu, wong shiu
wan yan » wang yan, nan yan, wai yan
yang yu » yang yue, yang yun, yang yi

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

• Performing a fuzzy search may retrieve terms with similar spellings: wan yan yang yu ((cheng yang) OR (chen yang)) john wong sau ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "wan yan yang yu ((cheng yang) OR (chen yang)) john wong sau ;".
• Adding a wildcard symbol may retrieve word variants: wan yan yang yu ((cheng yang) OR (chen yang)) john wong sau ;*.