Perhaps you should try some spelling variations:
chieu sang » chieu sach, chieu xanh, hieu lang
chieu tinh » trieu tinh, lieu tinh, chau tinh
hang cong » dang cong, hang nong, bang cong
tron thuc » trong thuc, trong thu
toan thuc » toan hoc, dan thuc, nhan thuc
tranh va » tranh van, trang va, trinh va
cong tac » cong ty
va hang » van hang, va nang, va lang

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((chieu sang) or (chieu tinh)) - canh tranh va hang cong tac ((tron thuc) OR (toan thuc))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sang) OR (chieu tinh)) - canh tranh va hang cong tac ((tron thuc) OR (toan thuc)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sang) or (chieu tinh)) - canh tranh va hang cong tac ((tron thuc) OR (toan thuc))".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sang) or (chieu tinh)) - canh tranh va hang cong tac ((tron thuc) OR (toan thuc))*.