Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
tang tai » hang tai, dung tai, sang tao
vai cua » dai cua, hai cua, lai cua
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
tai hoi » tai khoi, dai hoi, tai hai
ky tang » ky nang, ky dang, kho tang
su sach » so sach, vu sach
va cam » va cham, va cac, va cao
luc va » duc va, tuc va, loc va
ve cam » ve cham, ve cac, ve cai

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) or (su sach)) ky tang tai hoi. hieu ((ve cam) or (va cam)) luc va hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((thu sach) OR (su sach)) ky tang tai hoi. hieu ((ve cam) OR (va cam)) luc va hanh vai cua tre.
• Adding a wildcard symbol may retrieve word variants: ((thu sach) or (su sach)) ky tang tai hoi. hieu ((ve cam) or (va cam)) luc va hanh vai cua tre*.