Perhaps you should try some spelling variations:
thieu xanh » chieu xanh, hieu manh, thien anh
hanh tranh » canh tranh, hanh trinh, hanh trang
hoc thieu » toc thieu, hoc hien
tac thanh » bac thanh, cac thanh, tcc thanh
van dung » van dong, xay dung, tin dung
tac than » tam than, tac nhan, bac thanh
va dung » va duong, vat dung, va ung

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