Perhaps you should try some spelling variations:
nam thuc » nam thuoc, am thuc, nam tu
so sach » so sanh, bo sach, co sach
va hanh » van hanh, va thanh, va danh
doi cua » dai cua, hoi cua
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
va dinh » van dinh, va kinh, va tinh
cua te » cua tu
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach v nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) ((va hanh) or (va dinh)) doi cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach v nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) ((va hanh) OR (va dinh)) doi cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach v nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) ((va hanh) or (va dinh)) doi cua te".
• Adding a wildcard symbol may retrieve word variants: so sach v nang xa hoi. hieu ve ((nam thuc) OR (nam thu)) ((va hanh) or (va dinh)) doi cua te*.