Perhaps you should try some spelling variations:
quyen tap » tuyen tap, luyen tap, quyen cap
cach thuc » anh thuc, cac thu
cac thoi » cac toi, cac hop, cac tro
te cong » tai cong, thi cong, thu cong
cac chu » cac thu, cac che, cac khu
ve ky » va ky, ke ky
ve y » ve _, ke y, te y
dong » dung

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