Perhaps you should try some spelling variations:
khach nhanh » khach hang, cach nhanh, khac khanh
nhanh khong » nganh khong, nhan khong, nhanh hong
nhanh chong » thanh cong, khanh phong
chong khi » khong khi, cong khi, chong hiv
vu khach » vu khanh, vu khac, vay khach
su can » su cao, tu can, su han
su van » tu van, vu van

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu khach nhanh khong _ đong luc ) or ( ((su can) OR (su van)) nhanh chong khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu khach nhanh khong _ đong luc ) OR ( ((su can) OR (su van)) nhanh chong khi đong luc ))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( vu khach nhanh khong _ đong luc ) or ( ((su can) OR (su van)) nhanh chong khi đong luc ))*".