Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
hanh vai » hanh vi, hanh va, hanh tai
hieu va » lieu va, hieu qua
va tham » van tham, va cham, va thanh
vai cua » dai cua, hai cua, lai cua
cua tre » cua te, cuu tre, cua triet
sach v » sach va, sach y, sach 2
v nang » va nang, vu nang, van nang
luc va » tuc va, loc va
x hoi » xa hoi, o hoi, 5 hoi

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 v nang ((x hoi) OR (x ho)). hieu va tham ((duc va) or (luc va)) hanh vai cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach v nang ((x hoi) OR (x ho)). hieu va tham ((duc va) OR (luc va)) hanh vai cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach v nang ((x hoi) OR (x ho)). hieu va tham ((duc va) or (luc va)) hanh vai cua tre".
• Adding a wildcard symbol may retrieve word variants: thu sach v nang ((x hoi) OR (x ho)). hieu va tham ((duc va) or (luc va)) hanh vai cua tre*.