Perhaps you should try some spelling variations:
thanh trung » thanh tung
trung tran » trung tuan, trung thanh, trung tam
thien cac » thien cau, thieu cac, trien cac
tran dung » tran dang, tran hung, tran quang
hien cac » vien cac, hieu cac, dien cac
cong tac » cong ty
chan cau » phan cau, can cau, chinh cau

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: hoc ((hien cac) OR (thien cac)) - thanh trung tran dung ((cong san) OR (cong tac)) chan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hien cac) or (thien cac)) - thanh trung tran dung ((cong san) OR (cong tac)) chan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hien cac) or (thien cac)) - thanh trung tran dung ((cong san) OR (cong tac)) chan cau*.