Perhaps you should try some spelling variations:
thanh trung » thanh tung
cong thanh » dong thanh, cong trinh, cong tan
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
tac dung » sach dung, xay dung, van dung
cong san » cong tac
toan cau » 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: doc hieu xanh - thanh trung ((tac dung) OR (tin dung)) ((cong san) OR (cong thanh)) toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - thanh trung ((tac dung) OR (tin dung)) ((cong san) or (cong thanh)) toan cau~".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - thanh trung ((tac dung) OR (tin dung)) ((cong san) or (cong thanh)) toan cau*.