Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
hieu xanh » chieu xanh, hieu manh, hieu nganh
trinh qua » trinh quan, trinh cua, trinh quang
dung cong » dung trong
doc hieu » toc thieu, hoc thieu, hoc hien
qua dung » quang dung, su dung, qua song
cong dan » cong san, cong tan, huong dan
than cau » toan cau, phan cau, thanh chau
than cap » khan cap, thanh lap, thanh cac
thanh ca » thanh cha, thanh cac, thanh ha

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: doc hieu xanh - canh trinh qua dung cong dan ((than cau) or (((than cap) or (thanh ca))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - canh trinh qua dung cong dan ((than cau) OR (((than cap) OR (thanh ca)))).
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh trinh qua dung cong dan ((than cau) or (((than cap) or (thanh ca))))*.