Perhaps you should try some spelling variations:
hieu sach » chieu sach, hieu cach, dien sach
thong cac » trong cac, phong cach, thong cua
doc hieu » toc thieu, hoc thieu, hoc hien
anh tang » anh bang, anh dang, anh nang
tang cua » mang cua, hang cua, tang luan
cua bang » chua bang, cua ban, cua dang
cong ban » cong bang, cong tan, cong dan
cong san » cong tac
thai cac » thoai cac, tai cac, khai cac

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