Perhaps you should try some spelling variations:
canh trinh » canh tranh, hanh trinh, canh tinh
tong cong » trong cong, cong cong, dung cong
van thanh » van tuan
ban thanh » ban hanh, ban hang
ho chieu » theo chieu, hoc thieu, doi chieu
doc hieu » toc thieu, hoc thieu, hoc hien
trinh ve » trinh he, trinh va, trinh vi
ve tong » ve tuong, ve trong, ve cong

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 ve tong cong ((van thanh) OR (ban thanh)) dau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho chieu) or (doc hieu)) xanh - canh trinh ve tong cong ((van thanh) OR (ban thanh)) dau~".
• Adding a wildcard symbol may retrieve word variants: ((ho chieu) or (doc hieu)) xanh - canh trinh ve tong cong ((van thanh) OR (ban thanh)) dau*.