Perhaps you should try some spelling variations:
chong cong » cong cong, thong cong, cuong cong
hieu cach » hieu cac, chieu sach, hieu ca
dien sach » dien anh
tranh cua » doanh cua, manh cua
cua chong » cua cong, cua chung, cua khong
chinh can » chinh ban, chinh cau, chinh ngan
cong dan » cong san, cong tan, huong dan
chinh ca » chinh ta, chinh va, chinh tai

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 cach) or (dien sach)) - canh tranh cua chong cong dan ((chinh can) OR (chinh ca))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu cach) OR (dien sach)) - canh tranh cua chong cong dan ((chinh can) OR (chinh ca)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu cach) or (dien sach)) - canh tranh cua chong cong dan ((chinh can) OR (chinh ca))".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu cach) or (dien sach)) - canh tranh cua chong cong dan ((chinh can) OR (chinh ca))*.