Perhaps you should try some spelling variations:
thuoc sach » hoc sach, nuoc sach, thuat sach
thanh toan » thanh hoa, thanh san, tinh toan
hieu van » hieu va, thien van, lieu va
toan cua » than cua, tan cua, doanh cua
va thanh » gia thanh, ban thanh, va tinh
tu cach » tu cac
cam tuc » cam xuc, cam tu, nam thuc
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
ma hoi » mai hoi, xa hoi, ma hoa
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu cach) or (thuoc sach)) ky tang ma hoi. ((hieu ve) or (hieu van)) cam tuc va thanh toan cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu cach) OR (thuoc sach)) ky tang ma hoi. ((hieu ve) OR (hieu van)) cam tuc va thanh toan cua tre.
• Adding a wildcard symbol may retrieve word variants: ((tu cach) or (thuoc sach)) ky tang ma hoi. ((hieu ve) or (hieu van)) cam tuc va thanh toan cua tre*.