Perhaps you should try some spelling variations:
ban thanh » ban hanh
ban hang » ngan hang
te sach » toc sach
cam duc » cam xuc, cao duc, pham duc
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
ve cam » ve cham, ve cac, va cam

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((nang ma) OR (tang ma)) hoi. hieu ve cam duc ((ban thanh) or (ban hang)) vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((nang ma) OR (tang ma)) hoi. hieu ve cam duc ((ban thanh) OR (ban hang)) vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((nang ma) OR (tang ma)) hoi. hieu ve cam duc ((ban thanh) or (ban hang)) vai cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((nang ma) OR (tang ma)) hoi. hieu ve cam duc ((ban thanh) or (ban hang)) vai cua tre*.