Perhaps you should try some spelling variations:
ban hang » ngan hang
cham duc » pham duc, cham soc, pham duy
su sach » so sach, vu sach
va cham » va chat, va tham
sach tu » sach thu, cach tu, sach ty
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
nang xa » nang x, lang xa, mang xa
luu tre » luu tru, cuu tre, luy tre
vi luu » vi lua

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach tu ((nang xa) OR (nang ma)) hoi. hieu va cham duc ((ban hang) or (ban hanh)) vi luu tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu ((nang xa) OR (nang ma)) hoi. hieu va cham duc ((ban hang) OR (ban hanh)) vi luu tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu ((nang xa) OR (nang ma)) hoi. hieu va cham duc ((ban hang) or (ban hanh)) vi luu tre*".