Perhaps you should try some spelling variations:
thong dung » thong cong, thong thuong
hieu lang » chieu sang, hieu quang, nhieu tang
tranh van » tran van, trinh van, thanh van
van thong » van thuong, van phong, va thong
dung manh » duong manh, dung danh, hung manh
hop hieu » hop nhieu, hoi hieu, hoc thieu
toan tap » toan ban
toan cao » toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: hop hieu lang - canh tranh van thong dung manh ((toan tap) or (toan cao))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hop hieu lang - canh tranh van thong dung manh ((toan tap) OR (toan cao)).
• Adding a wildcard symbol may retrieve word variants: hop hieu lang - canh tranh van thong dung manh ((toan tap) or (toan cao))*.