Perhaps you should try some spelling variations:
knowing about » known about, know about, knowing your
minh thanh » binh thanh, binh thang
thanh daem » than daem, thanh dam
guang ying » huang ying, huang ting, huang yang
huang jing » huang ting, huang ying, wang jing
guan wei » hua wei, guan li, han wei

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: minh thanh daem guan wei ((guang ying) OR (huang jing)) knowing about ;~.
• Adding a wildcard symbol may retrieve word variants: minh thanh daem guan wei ((guang ying) or (huang jing)) knowing about ;*.