Perhaps you should try some spelling variations:
trung nhiem » trung hien, trong nhien, truong nghien
chieu xanh » chieu sach, chieu tinh, hieu manh
chieu sang » chieu sach, hieu lang, nhieu tang
trung hieu » thuong hieu, trung kien, trong hiep
cong tan » cong tac, cong san, cong thanh
tran ban » tranh ban, tran van, toan ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: ho ((chieu xanh) or (chieu sang)) - thanh ((trung nhiem) OR (trung hieu)) trong cong tan tran ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ho ((chieu xanh) OR (chieu sang)) - thanh ((trung nhiem) OR (trung hieu)) trong cong tan tran ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "ho ((chieu xanh) or (chieu sang)) - thanh ((trung nhiem) OR (trung hieu)) trong cong tan tran ban".
• Adding a wildcard symbol may retrieve word variants: ho ((chieu xanh) or (chieu sang)) - thanh ((trung nhiem) OR (trung hieu)) trong cong tan tran ban*.