Perhaps you should try some spelling variations:
ban thanh » ban hanh, ban hang
chet duoc » che duoc, cho duoc, che quoc
thu sach » tu sach, thuat sach, thuoc sach
duoc ban » duc ban, quoc ban, buoc ban
bai cua » ban cua, bai ca, hai cua
hieu va » lieu va, hieu qua
sach ky » sac ky, sach y, sach ty
hieu ve » hieu van
nang ma » tang ma, sang ma, nang cao
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: thu sach ky nang ma hoi. ((hieu ve) or (hieu va)) chet duoc ban thanh ((bai cua) or (dai cua)) tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach ky nang ma hoi. ((hieu ve) OR (hieu va)) chet duoc ban thanh ((bai cua) OR (dai cua)) tre.
• Adding a wildcard symbol may retrieve word variants: thu sach ky nang ma hoi. ((hieu ve) or (hieu va)) chet duoc ban thanh ((bai cua) or (dai cua)) tre*.