Perhaps you should try some spelling variations:
ban hang » ngan hang
cham duc » pham duc, cham soc, pham duy
tu sach » thu sach, su sach, te sach
hien tu » khien tu, dien tu
sach ky » sac ky, sach y, sach ty
hieu tu » chieu tu, hieu tuc, lieu tu
sang ma » tang ma, nang ma, sang tao
ky sang » ky nang, ky dang, ky tang
ma hoi » mai hoi, xa hoi, ma hoa
may va » may vi, day va
thiet » thieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach ky sang ma hoi. ((hieu tu) or (hien tu)) cham duc ((ban hanh) or (ban hang)) may va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky sang ma hoi. ((hieu tu) OR (hien tu)) cham duc ((ban hanh) OR (ban hang)) may va thiet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky sang ma hoi. ((hieu tu) or (hien tu)) cham duc ((ban hanh) or (ban hang)) may va thiet*.