Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hieu vach » hieu cach, chieu sach, hieu van
trung cua » truong cua, trung tuan, dung cua
trung cap » truong cao, trung tam
cong tan » cong tac, cong san, cong thanh
tan than » tan thanh, tan tran, ban than
than cau » toan cau, phan cau, than cap
hieu va » lieu va, hieu qua

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu vach) or (hieu va)) - thanh ((trung cua) or (trung cap)) nhung cong tan than cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu vach) OR (hieu va)) - thanh ((trung cua) OR (trung cap)) nhung cong tan than cau.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu vach) or (hieu va)) - thanh ((trung cua) or (trung cap)) nhung cong tan than cau*.