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