Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
canh trinh » canh tranh, hanh trinh, canh tinh
doi chieu » doi chi, ho chieu, mot chieu
doc hieu » toc thieu, hoc thieu, hoc hien
trinh va » trinh van, trinh vat, trinh ve
cong tan » cong tac, cong san, cong thanh
hang dau » hang va, hang tai

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: ((doi chieu) OR (doc hieu)) xanh - canh trinh va nhung cong tan ((hang dau) OR (phan tu))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((doi chieu) OR (doc hieu)) xanh - canh trinh va nhung cong tan ((hang dau) or (phan tu))~".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doc hieu)) xanh - canh trinh va nhung cong tan ((hang dau) or (phan tu))*.