Perhaps you should try some spelling variations:
quyen tap » tuyen tap, luyen tap, quyen cap
cach thoi » cac thoi, cach thuc, cach noi
cac khoi » cac thoi, cac khoan, hoc khoi
anh kiem » anh kien, khanh kiem, nganh kiem
thi cong » tai cong, thien cong
do anh » do sanh, do danh
kiem y » hiem 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 khoi) OR (cach thoi)) đe do anh kiem y ((thi cong) or (thu cong)) cong~.
• If you are trying to use Boolean operators, they must be ALL CAPS: quyen tap ((cac khoi) OR (cach thoi)) đe do anh kiem y ((thi cong) OR (thu cong)) cong.
• The words AND, OR and NOT may confuse the search; try adding quotes: "quyen tap ((cac khoi) OR (cach thoi)) đe do anh kiem y ((thi cong) or (thu cong)) cong".
• Adding a wildcard symbol may retrieve word variants: quyen tap ((cac khoi) OR (cach thoi)) đe do anh kiem y ((thi cong) or (thu cong)) cong*.