Perhaps you should try some spelling variations:
sach ngan » sach ngon, sach nha, sach han
ngan hoa » nganh hoa, nhan hoa, nganh khoa
vu sach » vu bach, su sach, vu khach
so sach » so sanh, bo sach, co sach
hoa khi » hoa phi, hoa hi, hoa thi
my chi » ly chi, y chi
ky khi » ky thi, ly khi

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( vu sach ngan ((my chi) or (ky khi)) đong luc ) or ( so sach ngan hoa khi đong luc ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( vu sach ngan ((my chi) OR (ky khi)) đong luc ) OR ( so sach ngan hoa khi đong luc )).
• Adding a wildcard symbol may retrieve word variants: (( vu sach ngan ((my chi) or (ky khi)) đong luc ) or ( so sach ngan hoa khi đong luc ))*.