Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
mai hoi » mai khoi, dai hoi, lai hoi
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 7 tang
nam lo » nam bo, nam so, nam co

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