Perhaps you should try some spelling variations:
cong cong » cong dong, trong cong, dung cong
cac khoi » cac thoi, cac khoan, cach thoi
cac che » cac he, cac chien, cac chat
cac khu » cac thu, cac kieu
ban ve » ban va
ky thu » ly thu, ky thi, ky thuat
y thu » ly thu, y thuc, _ thu
tuyen » truyen, quyen

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: tuyen tap ((cac che) or (((cac khu) OR (cac khoi)))) đe co ban ve ((y thu) or (ky thu)) cong cong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tuyen tap ((cac che) OR (((cac khu) OR (cac khoi)))) đe co ban ve ((y thu) OR (ky thu)) cong cong.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tuyen tap ((cac che) or (((cac khu) OR (cac khoi)))) đe co ban ve ((y thu) or (ky thu)) cong cong".
• Adding a wildcard symbol may retrieve word variants: tuyen tap ((cac che) or (((cac khu) OR (cac khoi)))) đe co ban ve ((y thu) or (ky thu)) cong cong*.