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 tac » cong ty
chai tu » cai tu, choi tu, chay tu

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)) xanh - canh trinh va nhung cong tac ((chai tu) or (phan tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doi chieu) OR (doc hieu)) xanh - canh trinh va nhung cong tac ((chai tu) 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 tac ((chai tu) or (phan tu))".
• Adding a wildcard symbol may retrieve word variants: ((doi chieu) OR (doc hieu)) xanh - canh trinh va nhung cong tac ((chai tu) or (phan tu))*.