Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, hieu cac
dien sach » dien anh
tranh cua » doanh cua, manh cua
cua thong » cua thuong, cua khong, cua tong
chinh cau » chinh chau, chinh ca, chinh can
cong dan » cong tan, huong dan, cong dong
cong san » cong tac

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