Perhaps you should try some spelling variations:
chieu sach » chinh sach, chieu sang, chieu xanh
canh trinh » canh tranh, hanh trinh, canh tinh
tong toan » trong toan, bong toan, cong toan
toan phan » thanh phan, toan ban, hoa phan
trinh va » trinh van, trinh vat, trinh ve
phan cau » phan dau, phan cac, phan tu
va han » va phan, van han, va hanh

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 (chiet tach)) - canh trinh va han tong toan phan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "theo ((chieu sach) OR (chiet tach)) - canh trinh va han tong toan phan cau".
• Adding a wildcard symbol may retrieve word variants: theo ((chieu sach) OR (chiet tach)) - canh trinh va han tong toan phan cau*.