Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
canh tinh » hanh tinh, manh tinh, canh tranh
bang cong » dang cong, bang song, hang cong
dan toan » dan than, manh toan, xuan toan
van toan » van tuan, van tan, van thanh
tinh da » tinh va, tinh gia, tinh lao
da bang » dau bang, da nang, da dang

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 ((chieu sach) OR (chiet tach)) - canh tinh da bang cong ((dan toan) OR (van toan)) cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) OR (chiet tach)) - canh tinh da bang cong ((dan toan) or (van toan)) cau~".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) OR (chiet tach)) - canh tinh da bang cong ((dan toan) or (van toan)) cau*.