Perhaps you should try some spelling variations:
quyen tap » tuyen tap, luyen tap, quyen cap
cach tieu » sach thieu, cach bien, cach tu
cong cong » cong dong, trong cong, dang cong
dung cong » dung trong
cac chat » cao chat, cac thuat, cac nha
ke y » ke ky, ke o
ve y » ve ky, ve _, te y

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