Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu sach » chieu sach, thien hach, hieu cach
chiet tach » chieu sach
thong cong » trong cong, tong cong, thong thong
trung cua » truong cua, trung tuan, trung cap
cua thong » cua thuong, cua khong, cua tong
cong tan » cong tac, cong san, cong thanh
than cau » phan cau, than cap, thanh chau
toan cau » toan cao, toan ban, toan tap

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 (chiet tach)) - thanh trung cua thong cong tan ((than cau) OR (toan cau))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (chiet tach)) - thanh trung cua thong cong tan ((than cau) OR (toan cau)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((thieu sach) or (chiet tach)) - thanh trung cua thong cong tan ((than cau) OR (toan cau))".
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (chiet tach)) - thanh trung cua thong cong tan ((than cau) OR (toan cau))*.