Perhaps you should try some spelling variations:
luyen tap » tuyen tap, luyen thi
cac khoi » cac thoi, cac khoan, cach thoi
thi cong » tai cong, thien cong
cac thu » cach thuc, cac thoi
hai thi » ha thi, hoi thi, tai thi
ban ve » ban va
ve hai » ve khai, ve cai, vu hai
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: luyen tap ((cac khoi) or (cac thu)) đe co ban ve hai thi cong dong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: luyen tap ((cac khoi) OR (cac thu)) đe co ban ve hai thi cong dong*.