Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » ho chieu, mot chieu, thi chieu
trinh vat » trinh van, trinh luat, sinh vat
dang cong » dung cong
doc hieu » toc thieu, hoc thieu, hoc hien
vat dang » van dang, vat dung, va dang
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap
doi chi » doi khi

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))) or (doi chi)) xanh - canh trinh vat dang cong dan toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((((doi chieu) OR (doc hieu))) OR (doi chi)) xanh - canh trinh vat dang cong dan toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((doi chieu) OR (doc hieu))) or (doi chi)) xanh - canh trinh vat dang cong dan toan cau".
• Adding a wildcard symbol may retrieve word variants: ((((doi chieu) OR (doc hieu))) or (doi chi)) xanh - canh trinh vat dang cong dan toan cau*.