Perhaps you should try some spelling variations:
thanh trung » thanh tung
chieu sach » chinh sach, chiet tach, chieu sang
hieu sach » hieu cach, dien sach, hieu cac
trung vat » trung va, trung van, trong vat
dung cong » dung trong
vat dung » van dung, va dung, viet dung
cong tan » cong tac, cong san, cong thanh
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) OR (chieu sach)) - thanh trung vat dung cong tan ((toan cau) OR (toan ban))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc ((hieu sach) OR (chieu sach)) - thanh trung vat dung cong tan ((toan cau) or (toan ban))~".
• Adding a wildcard symbol may retrieve word variants: doc ((hieu sach) OR (chieu sach)) - thanh trung vat dung cong tan ((toan cau) or (toan ban))*.