Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
dang cong » dung cong
doc hieu » toc thieu, hoc thieu, hoc hien
ho chieu » theo chieu, hoc thieu, doi chieu
trinh va » trinh van, trinh vat, trinh ve
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cau » toan cau, phan cau, than cap
va dang » van dang, va nang, va lang

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) or (ho chieu)) xanh - canh trinh va dang cong dan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (ho chieu)) xanh - canh trinh va dang cong dan than cau.
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (ho chieu)) xanh - canh trinh va dang cong dan than cau*.