Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
hieu van » hieu va, thien van, lieu va
va hanh » van hanh, va thanh, va danh
cham lo » cham o, cam lo, cham soc
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, ma hoa, me hoi
y tang » ky tang, 6 tang, 7 tang
cam ly » tam ly, cam ky, cam lo

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 y tang ((ma hoi) or (xa hoi)). hieu van ((cham lo) or (cam ly)) va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y tang ((ma hoi) OR (xa hoi)). hieu van ((cham lo) OR (cam ly)) va hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: thu sach y tang ((ma hoi) or (xa hoi)). hieu van ((cham lo) or (cam ly)) va hanh vai cua tre*.