Perhaps you should try some spelling variations:
quyen tap » tuyen tap, luyen tap, huyen tam
quyen cap » quyen cach, huyen cao, quyen con
cong cong » cong dong, trong cong, dung cong
cac chu » cac che, cac khu, ca chu
cac thu » cach thuc, cac thoi
vat y » vat ly, vat _
va y » va ky, va my, va ly

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