Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
vang thanh » van thanh, dang thanh, nang thanh
tang thanh » dang thanh, trung thanh, hoang thanh
trinh vat » trinh van, trinh luat, sinh vat
tong cong » trong cong, cong cong, dung cong
ho chieu » theo chieu, hoc thieu, doi chieu
doc hieu » toc thieu, hoc thieu, hoc hien
vat tong » vat trong, va tong, vat dong

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

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