Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
trong tap » trong thap, tong tap, trong tan
chi sach » chinh sach, co sach, moi sach
cua dung » cua dong, qua dung, cua rung
cua dang » cua cong, cua ban
tap toan » tap doan, tap quan, bai toan
toan cau » toan cao, toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: doi ((chi sach) or (chieu sach)) - canh tranh ((cua dung) OR (cua dang)) trong tap toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi ((chi sach) OR (chieu sach)) - canh tranh ((cua dung) OR (cua dang)) trong tap toan cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doi ((chi sach) or (chieu sach)) - canh tranh ((cua dung) OR (cua dang)) trong tap toan cau".
• Adding a wildcard symbol may retrieve word variants: doi ((chi sach) or (chieu sach)) - canh tranh ((cua dung) OR (cua dang)) trong tap toan cau*.