Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
tong cong » trong cong, cong cong, dang cong
dung cong » dung trong
tranh va » tranh van, trang va, trinh va
dan toan » van toan, dan than, manh toan
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 chieu sach - canh tranh va ((tong cong) or (dung cong)) dan toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - canh tranh va ((tong cong) OR (dung cong)) dan toan cao.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - canh tranh va ((tong cong) or (dung cong)) dan toan cao*.