Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu xanh
chieu sang » chieu xanh, hieu lang, nhieu tang
thanh tung » thanh cong
hang cong » dang cong, hang nong, bang cong
tan gian » tran gian, van gian, tan giao
tung va » trung va, tuong va, dung va
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 sach) or (chieu sang)) - thanh tung va hang cong ((tan gian) OR (dan gian)) cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((chieu sach) OR (chieu sang)) - thanh tung va hang cong ((tan gian) OR (dan gian)) cao.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) or (chieu sang)) - thanh tung va hang cong ((tan gian) OR (dan gian)) cao".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) or (chieu sang)) - thanh tung va hang cong ((tan gian) OR (dan gian)) cao*.