Perhaps you should try some spelling variations:
canh thanh » canh tranh, danh thanh, anh thanh
hieu sach » chieu sach, hieu cach, dien sach
doc hieu » toc thieu, hoc thieu, hoc hien
can bang » can ban, van ban, von bang
cao bang » cao dang, cao tang, cao nang
cong dan » cong san, cong tan, huong dan
toan cau » toan cao, toan ban, toan tai
toan tap » toan ban

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 - canh thanh ((can bang) or (cao bang)) cong dan ((toan cau) or (toan tap))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc hieu sach - canh thanh ((can bang) OR (cao bang)) cong dan ((toan cau) OR (toan tap)).
• Adding a wildcard symbol may retrieve word variants: doc hieu sach - canh thanh ((can bang) or (cao bang)) cong dan ((toan cau) or (toan tap))*.