Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
tranh hua » tranh chua, tranh cua, tranh ha
hua khong » hoa khong, cua khong, hoac khong
cong vang » cong lang, cong quang, cong ngang
chinh can » chinh ca, chinh ban, chinh cau
cong van » cong san, song van, cong tan

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 hua khong ((cong van) or (cong vang)) chinh can~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - canh tranh hua khong ((cong van) OR (cong vang)) chinh can.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - canh tranh hua khong ((cong van) or (cong vang)) chinh can*.