Perhaps you should try some spelling variations:
thanh trung » thanh tung
nhung cong » dung cong, thong cong, hang cong
hieu tinh » chieu tinh, lieu tinh, kieu tinh
doc hieu » toc thieu, hoc thieu, hoc hien
trung ha » trung hoc, trung tam, trung cap
ha nhung » hoa nhung, hay nhung, pha nhung
cong dan » cong san, cong tan, huong dan
than cap » khan cap, thanh lap, thanh cac
phan dau » phan tu
hang dau » hang va, hang tai

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 tinh - thanh trung ha nhung cong dan ((than cap) OR (((phan dau) OR (hang dau))))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc hieu tinh - thanh trung ha nhung cong dan ((than cap) or (((phan dau) OR (hang dau))))~".
• Adding a wildcard symbol may retrieve word variants: doc hieu tinh - thanh trung ha nhung cong dan ((than cap) or (((phan dau) OR (hang dau))))*.