Perhaps you should try some spelling variations:
thieu sach » chieu sach, thien hach, hieu cach
trung cua » truong cua, trung tuan, trung cap
truong ca » truong cao, truong va, trong ca
hang cong » dang cong, hang nong, bang cong
hieu luc » hieu luat, hieu qua
cong tac » cong ty
tac than » tac thanh, tam than, tac nhan
than cau » toan cau, phan cau, than cap

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 (hieu luc)) - thanh ((trung cua) or (truong ca)) hang cong tac than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((thieu sach) OR (hieu luc)) - thanh ((trung cua) OR (truong ca)) hang cong tac than cau.
• Adding a wildcard symbol may retrieve word variants: hoc ((thieu sach) or (hieu luc)) - thanh ((trung cua) or (truong ca)) hang cong tac than cau*.