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
chinh can » chinh ca, chinh ban, chinh ngan
chinh cau » chinh chau, chinh ca, chinh tai
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) OR (chinh cau))~.
• 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) OR (chinh cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) or (dien sach)) - canh tranh cua chung cong dan ((chinh can) OR (chinh cau))".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) or (dien sach)) - canh tranh cua chung cong dan ((chinh can) OR (chinh cau))*.