Perhaps you should try some spelling variations:
luyen tap » tuyen tap, luyen thi
cong cong » cong dong, trong cong, dang cong
dung cong » dung trong
tac cho » tac chon, dac cho, tap cho
tai che » tai chi, tai he, cai chet
ban ve » ban va
ky thu » ly thu, ky thi, ky thuat
ban ke » ban kem, ban le, ban ky

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

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