Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sach » thien hach, hieu cach, theo sach
chieu sach » chinh sach, chiet tach, chieu sang
cong thanh » dong thanh, cong tan, truong thanh
trung cua » truong cua, trung tuan, trung cap
cua bang » chua bang, cua ban, cua dang
san cau » van cau, ban cau, can cau

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoc ((thieu sach) or (chieu sach)) - thanh trung cua bang ((cong thanh) OR (cong trinh)) san cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (chieu sach)) - thanh trung cua bang ((cong thanh) OR (cong trinh)) san cau.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (chieu sach)) - thanh trung cua bang ((cong thanh) OR (cong trinh)) san cau".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (chieu sach)) - thanh trung cua bang ((cong thanh) OR (cong trinh)) san cau*.