Perhaps you should try some spelling variations:
thuong cong » thong cong, thuong con, thuong dong
chieu sang » chieu sach, chieu xanh, hieu lang
dien anh » tieng anh, dien dan
tranh va » tranh van, trang va, trinh va
cong tac » cong ty
doan cao » doanh cao, doan cap, hoang cao
toan cao » toan ban, toan tap

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: theo ((dien anh) OR (chieu sang)) - canh tranh va thuong cong tac ((doan cao) OR (toan cao))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((dien anh) or (chieu sang)) - canh tranh va thuong cong tac ((doan cao) OR (toan cao))~".
• Adding a wildcard symbol may retrieve word variants: theo ((dien anh) or (chieu sang)) - canh tranh va thuong cong tac ((doan cao) OR (toan cao))*.