Perhaps you should try some spelling variations:
hanh tranh » canh tranh, hanh trinh, hanh trang
hieu xanh » chieu xanh, hieu manh, hieu nganh
tranh cua » doanh cua, manh cua
doc hieu » toc thieu, hoc thieu, hoc hien
cua dung » cua dang, cua dong, qua dung
cong dan » huong dan, cong dong, cong tac
cong san » cong tac
cong tan » cong tac, cong thanh, cong ty
than tap » toan tap, han tap, phan 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 - hanh tranh cua dung ((((cong dan) OR (cong san))) OR (cong tan)) than tap~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu xanh - hanh tranh cua dung ((((cong dan) OR (cong san))) or (cong tan)) than tap~".
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - hanh tranh cua dung ((((cong dan) OR (cong san))) or (cong tan)) than tap*.