Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
tran tuan » tran xuan, tran thanh, tranh luan
dung cong » dung trong
cong tac » cong ty
toan tai » toan tap, doanh tai, toan ban
toan cao » toan ban, toan tap

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 thieu xanh - hanh ((tran tuan) OR (tran quang)) dung cong tac ((toan tai) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc thieu xanh - hanh ((tran tuan) OR (tran quang)) dung cong tac ((toan tai) or (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh ((tran tuan) OR (tran quang)) dung cong tac ((toan tai) or (toan cao))*.