Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
dung cong » dung trong
tranh tu » trinh tu, tran tu, thanh tu
cong tac » cong ty
toan tai » toan tap, doanh tai, toan ban
toan cao » toan ban, toan tap
tu dung » tuc dung, tu duong, su dung

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: hoc hien xanh - canh tranh tu dung cong tac ((toan tai) OR (toan cao))~.
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - canh tranh tu dung cong tac ((toan tai) or (toan cao))*.