Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
nganh cong » nhanh chong, thanh cong
sach nhanh » cach nhanh, sach nha, sach tranh
chong khi » chong hiv, chong lai, chong li
khong khi » khong he
cong khi » cong thai, co khi, cong ha
te sach » toc sach
tu sach » thu sach, su sach, tu cach

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

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