Perhaps you should try some spelling variations:
sach nganh » sach ngan, sach tranh, sach danh
cac nganh » hoc nganh
toc sach » hoc sach, doc sach, thuoc sach
cong khi » cong thai, khong khi, cong hai
nganh co » nganh cong, nganh hoa, nganh y
cong ha » cong hoa, dong ha, cong tac
ve cac » va cac, vien cac

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

• If you are trying to use Boolean operators, they must be ALL CAPS: (( toc sach nganh ((cong khi) OR (cong ha)) đong luc ) OR ( ve cac nganh co khi đong luc ))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( toc sach nganh ((cong khi) OR (cong ha)) đong luc ) or ( ve cac nganh co khi đong luc ))~".
• Adding a wildcard symbol may retrieve word variants: (( toc sach nganh ((cong khi) OR (cong ha)) đong luc ) or ( ve cac nganh co khi đong luc ))*.