Perhaps you should try some spelling variations:
tieu sach » chieu sach, dien sach, te sach
trung vat » trung va, trung van, truong van
trong vat » trong van, trong va, trong dat
dung cong » dung trong
cong dan » cong san, cong tan, huong dan
dan than » dan chan, ban than, van than
than cap » khan cap, thanh lap, thanh cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo tieu sach - thanh ((trung vat) or (trong vat)) dung cong dan than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo tieu sach - thanh ((trung vat) OR (trong vat)) dung cong dan than cap.
• Adding a wildcard symbol may retrieve word variants: theo tieu sach - thanh ((trung vat) or (trong vat)) dung cong dan than cap*.