Perhaps you should try some spelling variations:
chung cong » nhung cong, chong cong, phung cong
hieu sach » chieu sach, hieu cach, hieu cac
dien sach » dien anh
tranh cua » doanh cua, manh cua
cua chung » cua nhung, luan chung, luat chung
dan chinh » dang chinh, lan chinh, van chinh
chinh can » chinh ca, chinh ban, chinh cau
cong dan » cong san, cong tan, huong dan

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu sach) or (dien sach)) - canh tranh cua chung cong dan chinh can~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (dien sach)) - canh tranh cua chung cong dan chinh can.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) or (dien sach)) - canh tranh cua chung cong dan chinh can*.