Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » doi chi, ho chieu, mot chieu
dang cong » dung cong
doc hieu » toc thieu, hoc thieu, hoc hien
trinh va » trinh van, trinh vat, trinh ve
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
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: ((doi chieu) OR (doc hieu)) xanh - canh trinh va dang cong dan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doc hieu)) xanh - canh trinh va dang cong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doc hieu)) xanh - canh trinh va dang cong dan toan cau*.