Perhaps you should try some spelling variations:
vu sach » vu bach, su sach, vu khach
va danh » va dinh, va dan, dia danh
sach ky » sac ky, sach y, sach ty
va hanh » van hanh, va thanh, ban hanh
tang ma » mang may, tang van
hieu ve » hieu va, hieu van
ky tang » ky nang, ky dang, kho tang
ve dam » ven dam, ke dam, va dam
dam tu » nam tu, cam tu, tam tu
ma hoi » mai hoi, xa hoi, ma hoa
vi va » vi van, vai va, bi va
vu va » vu van, tu va, su va
thiet » thieu

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

• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky tang ma hoi. hieu ve dam tu ((va hanh) OR (va danh)) ((vi va) OR (vu va)) thiet~.
• Adding a wildcard symbol may retrieve word variants: vu sach ky tang ma hoi. hieu ve dam tu ((va hanh) or (va danh)) ((vi va) or (vu va)) thiet*.