Perhaps you should try some spelling variations:
so sach » so sanh, bo sach, co sach
sach ky » sac ky, sach y, sach ty
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hieu va » lieu va, hieu qua
bai bao » tai bao, bat bao, hoai bao
va hanh » van hanh, va thanh, va danh
ban cua » ban quan
bao va » bao ve, tao va, ban va

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 ky ((nang ma) or (sang ma)) hoi. hieu va bai bao va hanh ((gian xu) or (ban cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ky ((nang ma) OR (sang ma)) hoi. hieu va bai bao va hanh ((gian xu) OR (ban cua)) tre.
• Adding a wildcard symbol may retrieve word variants: so sach ky ((nang ma) or (sang ma)) hoi. hieu va bai bao va hanh ((gian xu) or (ban cua)) tre*.