Perhaps you should try some spelling variations:
quyen tap » tuyen tap, luyen tap, quyen cap
thai cong » tai cong, thi cong, thanh cong
cong cong » cong dong, trong cong, dung cong
quyen con » quyen cong, tuyen chon, nguyen con
cac khoi » cac thoi, cac khoan, cach thoi
ve y » ve ky, ve _, te y
ke y » ke ky, ke o

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

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