Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » doi chi, mot chieu, thi chieu
dang cong » dung cong
doc hieu » toc thieu, hoc thieu, hoc hien
ho chieu » theo chieu, hoc thieu, mot chieu
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 tap » toan ban
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) OR (doi chieu)))) xanh - canh trinh va dang cong dan toan tap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc hieu) OR (((ho chieu) OR (doi chieu)))) xanh - canh trinh va dang cong dan toan tap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doc hieu) or (((ho chieu) OR (doi chieu)))) xanh - canh trinh va dang cong dan toan tap".
• Adding a wildcard symbol may retrieve word variants: ((doc hieu) or (((ho chieu) OR (doi chieu)))) xanh - canh trinh va dang cong dan toan tap*.