Perhaps you should try some spelling variations:
thanh trung » thanh tung
hieu sach » chieu sach, hieu cach, dien sach
trung vat » trung va, trung van, trong vat
doc hieu » toc thieu, hoc thieu, hoc hien
vat dung » van dung, va dung, viet dung
cong tan » cong tac, cong thanh, cong ty
cong san » cong tac
toan cau » toan cao, toan tap, toan tai
toan ban » van ban

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

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