Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hoc thieu » toc thieu, hoc hien
hanh tran » hanh trang, thanh tran, hanh tram
hang cong » dang cong, hang nong, bang cong
dung cong » dung trong
tac toan » tap toan, tam toan, hach toan
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc thieu xanh - hanh tran quang ((hang cong) or (dung cong)) tac toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc thieu xanh - hanh tran quang ((hang cong) OR (dung cong)) tac toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc thieu xanh - hanh tran quang ((hang cong) or (dung cong)) tac toan cao*.