Perhaps you should try some spelling variations:
yuan cheng » yuan chang, huang cheng, yu cheng
cheng yan » cheng han, cheng guan, chen yang
wang ying » wang yang, wang jing, wang ning
wang yong » wang yang, wang hyoung, wang yan
wong shiu » wong siu, cong shu, song shin
kong saur » kong sar, kong siu, kong your
yan yuan » yan guan, fang yuan, nan 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 yuan cheng yan ((wang ying) OR (wang yong)) jin ((wong shiu) OR (kong saur)) ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "yan yuan cheng yan ((wang ying) OR (wang yong)) jin ((wong shiu) or (kong saur)) ;~".
• Adding a wildcard symbol may retrieve word variants: yan yuan cheng yan ((wang ying) OR (wang yong)) jin ((wong shiu) or (kong saur)) ;*.