Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
hieu van » thien van, lieu va, hieu ve
trung va » truong va, trang va, trung ha
cong san » cong tac
san than » sang than, san thanh, ban than
than cap » khan cap, thanh lap, thanh cac
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: hoc ((hieu va) or (hieu van)) - thanh trung va nhung cong san than cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu va) OR (hieu van)) - thanh trung va nhung cong san than cap.
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu va) or (hieu van)) - thanh trung va nhung cong san than cap*.