Perhaps you should try some spelling variations:
chieu sang » chieu xanh, hieu lang, nhieu tang
chieu sach » chinh sach, chiet tach, chieu xanh
hang cong » dang cong, hang nong, bang cong
van hang » van khang, van hoang, van thang
cong tac » cong ty
tac than » tac thanh, tam than, tac nhan
than cao » toan cao, thai cao, than cap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((chieu sang) OR (chieu sach)) - ((thanh tung) or (thanh cong)) van hang cong tac than cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((chieu sang) OR (chieu sach)) - ((thanh tung) OR (thanh cong)) van hang cong tac than cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((chieu sang) OR (chieu sach)) - ((thanh tung) or (thanh cong)) van hang cong tac than cao".
• Adding a wildcard symbol may retrieve word variants: hoc ((chieu sang) OR (chieu sach)) - ((thanh tung) or (thanh cong)) van hang cong tac than cao*.