Perhaps you should try some spelling variations:
cach thuc » anh thuc
quyen con » quyen cong, tuyen chon, nguyen con
cong cong » cong dong, trong cong, dung cong
cac chu » cac che, cac khu, ca chu
cac thu » cac thoi
ban ve » ban va
ky thu » ly thu, ky thi, ky thuat
y thu » ly thu, y thuc, _ thu

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

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