Perhaps you should try some spelling variations:
trung cong » truong cong, trung uong, trang cong
ban tieng » van tien, ban tinh, va 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
ban ve » ban va
ve ban » te ban, va ban, ve bao

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 ((trung cong) OR (trong 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 ((trung cong) OR (trong cong))~".
• Adding a wildcard symbol may retrieve word variants: xuyen tac ((cac kieu) or (cac thoi)) đe co ban ve ban tieng ((trung cong) OR (trong cong))*.