Perhaps you should try some spelling variations:
thanh tung » thanh cong
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
cong dan » cong tan, huong dan, cong dong
cong tac » cong ty
toan cau » toan cao, toan ban, toan tap
tung va » trung va, tuong va, dung va

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 tung va nhung ((cong dan) OR (((cong san) OR (cong tac)))) toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - thanh tung va nhung ((cong dan) or (((cong san) OR (cong tac)))) toan cau~".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - thanh tung va nhung ((cong dan) or (((cong san) OR (cong tac)))) toan cau*.