Perhaps you should try some spelling variations:
ban thanh » ban hanh
ban hang » ngan hang
su sach » so sach, vu sach
lai cua » dai cua, hai cua, lai chau
vai cua » dai cua, hai cua, bai cua
sach ty » sach y, sach tu, sach thu
cac duc » cac du, cao duc, cac dac
hieu va » lieu va, hieu qua
nang ma » tang ma, sang ma, nang cao
ty nang » ky nang, ty xang, ty hang
ma hoi » mai hoi, xa hoi, ma hoa

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 ty nang ma hoi. hieu va cac duc ((ban thanh) or (ban hang)) ((vai cua) or (lai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty nang ma hoi. hieu va cac duc ((ban thanh) OR (ban hang)) ((vai cua) OR (lai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: su sach ty nang ma hoi. hieu va cac duc ((ban thanh) or (ban hang)) ((vai cua) or (lai cua)) tre*.