Perhaps you should try some spelling variations:
chieu sach » chinh sach, chiet tach, chieu sang
doi chieu » doc hieu, doi chi, ho chieu
dung cong » dung trong
trang va » hang va
tran van » luan van
cong dan » cong san, cong tan, huong dan
dan van » dang van, doan van, dao van

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 - hanh ((trang va) or (tran van)) dung cong dan van ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doi chieu sach - hanh ((trang va) OR (tran van)) dung cong dan van ban.
• Adding a wildcard symbol may retrieve word variants: doi chieu sach - hanh ((trang va) or (tran van)) dung cong dan van ban*.