Perhaps you should try some spelling variations:
boon chong » boon siong, joon chang
chong yung » chong yun, chang yun, zhong yong
yung chen » yun chen, yu chen, yulu chen
shang kai » shang hai
yang jie » yang jin, yang jui, yang jun
yang yi » yang jui
yang xi » yang jui
a boon » a book

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: a boon chong yung chen ((((((yang yi) OR (yang jie))) OR (yang xi))) OR (yang di)) shang kai ;~.
• Adding a wildcard symbol may retrieve word variants: a boon chong yung chen ((((((yang yi) or (yang jie))) or (yang xi))) or (yang di)) shang kai ;*.