Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, cac nganh
anh tranh » canh tranh, lanh tranh, anh thanh
cong thai » cong hai, cong thanh, cong tac
hong thai » hong ha, hinh thai
nganh co » nganh cong, nganh hoa, nganh y
co sach » bo sach, cuon sach, hoc sach
su anh » sua anh, vu anh, tu anh

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

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