Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
ban thanh » ban hanh, ban hang
hieu van » hieu va, thien van, lieu va
vai cua » dai cua, hai cua, lai cua
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
van cam » van nam, van lam, van cau
cua tre » cua te, cuu tre, cua triet
sach ky » sach y, sach ty, sach kem
tang ma » mang may, tang van
nang ma » sang ma, nang cao, mang may
sac ky » cac ky, sai ky

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

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