Perhaps you should try some spelling variations:
ban hanh » ban hang
sach ky » sac ky, sach y, sach ty
duc ban » duc tan, duc van, dua ban
cam duc » cam xuc, cao duc, pham duc
mai hoi » mai khoi, dai hoi, lai hoi
cua tre » cua te, cuu tre, cua triet
ma hoi » xa hoi, ma hoa, me hoi
va cam » va cham, va cac, va cao
sai ky » sac ky
vi cua » vai cua, di cua

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 (sai ky)) nang ((ma hoi) or (mai hoi)). lieu va cam duc ban hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach ky) OR (sai ky)) nang ((ma hoi) OR (mai hoi)). lieu va cam duc ban hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: tu ((sach ky) or (sai ky)) nang ((ma hoi) or (mai hoi)). lieu va cam duc ban hanh vi cua tre*.