Perhaps you should try some spelling variations:
trung cong » truong cong, trong cong, trung uong
ban tieng » ban tinh, va tieng, anh tieng
xuyen tac » xuyen tai, nguyen tac, thuyen tac
cac kieu » cach tieu, cac yeu, tac kiem
cac thoi » cac toi, cac hop, cac tro
van tien » toan tien, van hieu, van tuan
ban ve » ban va

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: xuyen tac ((cac kieu) OR (cac thoi)) đe co ban ve ((ban tieng) OR (van tien)) trung cong~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "xuyen tac ((cac kieu) or (cac thoi)) đe co ban ve ((ban tieng) OR (van tien)) trung cong~".
• Adding a wildcard symbol may retrieve word variants: xuyen tac ((cac kieu) or (cac thoi)) đe co ban ve ((ban tieng) OR (van tien)) trung cong*.