Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
cua thong » cua thuong, cua khong, suat thong
dan chinh » dang chinh, lan chinh, van chinh
chinh cau » chinh chau, chinh ca, chinh can
dien anh » tieng anh, dien dan
cua tong » cua cong, cua dong, cua nong
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 anh)) - canh tranh ((cua thong) or (cua tong)) cong dan chinh cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu sach) OR (dien anh)) - canh tranh ((cua thong) OR (cua tong)) cong dan chinh cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) or (dien anh)) - canh tranh ((cua thong) or (cua tong)) cong dan chinh cau*.