Perhaps you should try some spelling variations:
thuong cong » thong cong, thuong con, thuong dong
hieu xanh » chieu xanh, hieu manh, hieu nganh
doc hieu » toc thieu, hoc thieu, hoc hien
trinh va » trinh van, trinh vat, trinh ve
trang va » tran van, hang va
cong tac » cong ty
tac hang » tac vang, bac thang, tac chong
hang dau » hang va, hang tai

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 xanh - canh ((trinh va) or (trang va)) thuong cong tac hang dau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu xanh - canh ((trinh va) OR (trang va)) thuong cong tac hang dau.
• Adding a wildcard symbol may retrieve word variants: doc hieu xanh - canh ((trinh va) or (trang va)) thuong cong tac hang dau*.